The Up and Downs of Alola
Anyone who complains about "meme faces" has never watched a good anime or cartoon. There is zero downside to making the characters more lively and expressive; in fact, that's one of the key principles of animation; exaggeration.
Interesting how such a short statement can be packed with so much stuff that I'd end up writing one of my signature "long critique"-style posts.
So, I'll start by admitting that I've seen just a couple of animes in this young life of mine (not counting Pokémon) which, compared to a lot of other people around here, probably isn't that much. But, from the couple of animes that I've seen, none had such overly hyperbolic reactions from the characters in the shows (and, even if they did, they were nowhere near SM's level of overexaggeration and overabundance). Characters in A Restaurant to Another World or Overlord or That Time I Got Reincarnated as a Slime might occasionally have one or a few more characters having a somewhat exaggerated expression, but the characters' facial reactions in these cases were not blown out of proportion (not to mention that these instances usually happened once in a blue moon), unlike Sun & Moon, where a good portion of the characters' reactions are comedically overexaggerated (and there's also the fact that these funny faces happen almost constantly, to the point that we already passed the 3000 mark by the time of the Alola League). Even the Dragon Ball sagas and Naruto, two of the most popular and wildly beloved animes out there, don't have hyperbolic reactions (based on the few episodes/image galleries I've seen). And, even if they do, it's definitely not on the same level as SM, or else I would've heard about it (and you'd have to be completely loco to try and argue that these two (or the previous ones I mentioned) are terrible because they don't feature SM's silly facial expressions).
When it comes to western cartoons however, I've seen more than my fair shares of those and I can tell you that I've never seen the Sun & Moon-style """""funny""""" faces in cartoons (or at least not as often as you make it seem to be). I've never seen these kinds of faces in one of Genndy Tartakovsky's incredible shows. Or these kinds of expressions in the Ben 10 cartoons. Or this in Kim Possible. Or this in the Disney Princess films like Snow White or Cinderella or the Aladdin trilogy or, my personal favorite, The Princess and the Frog (yeah, I used to watch the as a boy and enjoy rewatching them from time to time; so what?). Or this in the Lion King duology or the Lion Guard. Or these in any of the Transformers cartoons (including the animes or the Japan-inspired ones, as far as I remember). Or this in My Little Pony or the Equestria Girls movies. Or this in Johnny Bravo. Or this in ThunderCats. And I could keep going on and on, but then this post might end up being far too long, so I'll assume that you got the point and move on. And, again, while some of them did have moments where the characters would react in a somewhat comically way, it wasn't as exagerate as SM's faces (and, also again, you'd have to be mad to say that stuff like Samurai Jack is bad because of a lack of "meme faces").
As for your "it's one of the key principles of animation" argument, that image of yours focuses on more aspects of animation than just hyperbolic reactions, like character movement, designs and lines of action, with exaggeration representing just one aspect. And there's also the fact that "exaggeration" is a pretty broad term in this case and that picture doesn't say that exaggeration = hyperbolic silly faces or how much exaggeration there needs to be in a character's design. In fact, from a certain point of view, one could say that the Pokémon anime already fitted the "exaggeration" part, thanks to the characters' anime eyes, anime hair and overly slim necks.
