Sure, it's not really very complicated; basically the flavours are often intense and whilst I don't personally like them, it's not like they're objectively bad, and they often score highly on the non-flavour/aroma aspects of a score sheet.
But allow me to add a large number of words that add almost nothing to the above ...
If you look at most of the prevailing score sheets around (ie. SCA and COE) they break down the score into many sections, which I like to think of as "flavour" and "structure". "Flavour" is basically flavour and aroma. "Structure" is everything else ie.
Arguably I guess "aftertaste" and "overall" are partly or probably "flavour", but this is my shorthand, not a real thing that exists in the world.
The point is that the flavour categories are maybe 20-40 out of 100, whilst the structure is like 60-80 out of 100. So even if I scored the fragrance and the flavour low, if it's an anaerobic natural, it probably has high body, sweetness, balanced acidity, etc, which may well mean that it makes up anything that it loses on flavour, so those things may offset each other and the coffee may not end up scoring notably lower because of anything.
But then we've got to look at how we actually score flavour and faults. And this sit in the context that good graders always feel a responsibility to the producers to be as fair as possible to them. Scoring isn't some exercise in reviewer ego, and, really, it's not designed to be an exercise in informing consumers. It's designed to be an exercise for achieving fairness between green coffee buyers and green coffee sellers. Scores can have real, far-reaching consequences for these people - if you look at the Specialty Coffee Transaction Guide, you will see that generally for the coffees covered by the donated data, price goes up with score, so an 88 point coffee might fetch 4x what an 80 point coffee fetches. So this is a serious responsibility - imagine that you had to look a coffee farmer in the eye and explain to them why they are going to earn 50% less than they expected from a year of labour! Imagine your boss doing the same to you in your job!
And this is the most difficult part of it. As much as everyone wants flavour scoring to be objective, it's pretty hard to get everyone calibrated to it. There are a few bright lines, like ferment, potato and phenolic are clearly defined defects and they get classified as "faults" or "taints" based on intensity, with corresponding score penalties. The SCA has an arguably more objective additional way of scoring this with uniformity; you assess 5 cups and they get 2 points each for "uniformity", so if one tastes unusually different (often a phenolic or similar) then it will lose points for uniformity regardless of if it is a fault or a taint (and in addition if it is). Because if your'e a roaster and you're selling a coffee, it's pretty reasonable to expect that each cup should taste the same. There's a loose rule that anything that tastes distinctively "non-coffee" can be considered bad, but that's hardly a hard and fast rule that's easily applied. I suppose in practice what this means is more that if something tastes like some sort of food or drink product that we commonly eat and that isn't considered off, then it's probably not something that is to be considered a fault or a taint. So flavours may not be a fault or a taint, but then you've still got to work out what they are actually scoring. So you sort of end up with flavours that you can't say are objectively bad, but they're usually pretty intense, so they probably need to score pretty high.
Let's go through an example:
Imagine a nice washed caturra. Some peach flavour, not particularly intense, super clean, crisp finish but not long in aftertaste, average body. Probably OK aroma and flavour scores, good scores on clean cup and balance, maybe 84-85 overall.
Now imagine an anaerobic natural. Pick two out of: vegemite, miso, balsamic vinegar, jackfruit, durian, sharpie, liquorice, bin juice fruits. Probably something with a little fruit. It's probably going to have quite a lot of intensity, and it's not like I'm going to be able to say the flavours are defects given what I've said above. So it probably scores pretty high on flavour and aroma by reason of intensity. Then if it has high body, average clean cup, does fairly well in the other categories, it's pretty easy for this coffee to land up around 87-88.
So that's why the coffees score that way. And that's a fair score, because that's just applying the rules as objectively and fairly to buyer and seller as you can. It's up to the buyers to understand how the sheets work, and if they are willing to reduce everything down to the final number and ignore all of the rest of the information on the sheet, that's their problem.
For me, personally, do I want a peachy, high acidity, snappy crisp cup or a jammy, thick, balsamic vinegar and durian cup? I prefer the former for it super clean and refreshing finish and familiar fruit aroma and I dislike the latter because I don't care about having more body in my coffee and I don't like those flavours; in particular, I personally find the wild flavour of durian a bit dirty. But there are many critiques that people could equally make about the 84 point coffee; it would probably be fair to say that everything about it is more difficult: it's more difficult to roast and more difficult to extract and to present well. You can further criticise it to say that even if you roast and extract it perfectly, your payoff isn't that much intensity of flavour and you might dislike the high acidity and average body. Conversely, people that like this anaerobic natural might really like the flavour, and when you open the bag of green coffee, it smells like what the cup tastes like already, so it doesn't take any great skill to roast and extract it to get immediately obvious and intense flavours into the cup, which are probably distinctive even through milk. And I might not like durian in my coffee, but many people do.
To be a little cynical for a moment, one thing that the triumph of intensely flavoured anaerobic naturals really illustrates is not about these coffees at all. These coffees are intense and distinctive; it makes perfect sense that these trade at a premium. Someone could have a superautomatic with the grinder set too coarse and these coffees will still deliver them a distinctive and intense taste experience, whereas that user could go through every single meek and perfectly clean coffee that I love and they will probably all taste the same and like sour lemon juice with that setup. So there are clearly markets where these coffees are fantastic. No argument. But we should expect better of coffee professionals. I totally get that the home brewer with a superauto may hate clean and mild coffees, but they should walk into any of the cafes that present themselves as the best of the best and they should be able to get a cup of the peachy caturra that is so well roasted and extracted that they are whacked in the face with peach aroma and they wonder "wow, why can't I brew these coffees this well at home?" Instead, it's pretty common for me to walk into cafes like this and have some baby barista breathlessly enthuse about the anaerobic natural and steer me away from the "boring" caturra, essentially a confession of the lack of skill and understanding of that business. The cafes that present themselves as coffee experts and have like $40k of brewing equipment should have the equipment, skill, understanding and coffee to present these coffees at their absolute best instead of needing to rely on heavily processed coffees to impress their customers. I mean, sure, they can serve the intense coffees as well, and no doubt many customers will choose them, but they should be so good at their art and craft that they can make an 85 point washed caturra a notable delicious experience for their customers that their customers are enthusiastic about.