But the real answer is they aren't inherently bad. People don't actually need it to conform to the past limitations. More that they want it to feel authentic to the nostalgic memory they have in their head.
For example, games like Shovel Knight go for an 8bit style, but they're not limited to an 8 bit color space, NES sprite limitations, etc.
https://www.gamedeveloper.com/design/breaking-the-nes-for-sh...
A post from the author about the remade art: https://la-mulana.com/en/blog/graphic_full_remake.html
Compared to the art from the screenshots on Wikipedia: https://en.m.wikipedia.org/wiki/La-Mulana
There's something to limited color space that those people do not seem to understand, be it the ones saying such critique, or the ones getting mad at it. We see color quantization in any realistic painting after the renaissance. Limiting the color space actually makes the pixel art look more realistic, because then every shade or shadow fits the overall drawings. Once you go Stardew Valley, sure it's pixel art, but just like a Picasso is great, it's not a Caravaggio, it's not "realistic" when it comes to how lighting reflects off surfaces.
Then there's the use of tiles/repeating background parts or having a full canvas where every pixel is unique. Although it's nice to look at, there's just too much information for the brain to process. That kind of art is nice, but in a game it's distracting. I personally call that kind of art pixel paintings and separate it from classic pixel art with tiles and limited colors.
It might be all just rose tinted glasses of nostalgia, but I firmly believe there's some science to what I just described. Look at any Caravaggio painting but especially portraits to see how limited the color space really is, how sometimes he uses shades of a color to give the impression of a very distant (color-space-wise) second color. It's really about that.
Adding lights from a lighting engine over the top of sprites with baked shading, might make a pretty image but it is not pushing pixel art forwards. Scaling and rotating can produce poor quality sprites.
P.s. Ashford is the best.