This hits two completely different issues at once; one relevant, one not so much IMO.
First, that some stats are useless for some classes isn't a problem: it naturally follows that someone with a bent for, say, fighting is going to want to be (or become) stronger and-or tougher than the average Sue and brains (while useful) and-or looks aren't likely to matter as much in the pursuit of becoming a better fighter. Flip that around with an arcane caster - if he's strong enough to carry his spellbooks around and is robust enough to not fall ill every other week, what more does he need physically? Here, all the development and training is most likely going to go into brain power.
The point is relevant
Because of burnout.
D&D is almost 50 years old. Video, board, war, TT, and mobile games have been using D&D tropes for almost as long.
It's not that Str-only fighters and Int-only wizards are bad. It's that many fans are bored of it. And since other media copied D&D, they were bored of it before even getting into D&D. And the more fans you pick up, the more bored fans you get.
And Zeus help you if you DM. I DMed so many dwarf fighter NPCs than I can count.
So it should be expected that someone wants to run a gnome barbarian, or Minotaur wizard, or tiefling monk, or goblin fighter who deals extra damage by carving sine waves in the air with their longsword, invoking Imotigen's Theory.
I'll say it again. "D&D. Suffering from Success Dj Khaled We the Best."