I have a hunch that most of the complaints are more focused on the Reddit-style post layout with nested comments. Which I could understand since this layout has been around for over a decade. However, I haven't seen a better layout and several other sites use this same setup. To just name a few of them; notabug.io, poal.co, voat.co, raddle.me, tildes.net, and thedonald.win.

Out of all of these only Tildes stand out to me for being incredibly minimalist and uses a slightly bigger font for comments. The others use a comparable font size to Saidit. So the only other things I see different is the color pallet and the maximum width on the comment blocks (I admit limiting the width makes it easier for me to read but I usually get around this by not full screening the browser). Overall nothing stands out enough for me to think that another Reddit-Alt found the mythical new modern look. So unless someone can provide an example of what they want or explicitly point out some aspect of the design I say just shrug off the complaints.