I think the issue was the feedback they got was "ASI tied to background is fine" which was said when floating ASI was still part of the plan and backgrounds were suggestions rather than hardwired. At some point, they changed the idea that background was going to be default customizable to fixed, and their compromise was to allow limited float among half the ability scores per background, which would be fine if they hadn't spent so much effort undoing prof mod per day in favor of ability mod per rest and making high ability scores more important, not less.
I remember the discussion or feedback being "more significant backgrounds are fine" or "backgrounds with actual feats are fine." I don't remember them having ASIs tied to backgrounds at any point in the playtest. (But I admit I don't recall anything after 6.)
I just don't understand why they don't just associate ASI with the character
class. Like what upsidedown thought process are they going through where they imagine that the most important character choices are made at level 1, and background has a significant effect on your attributes, but your class doesn't do anything at all? Like surely a Fighter or Wizard must have
done something to have acquired those proficiencies and abilities. Why would background affect ASIs and not class?
Do they think making a Soldier-Wizard have to choose Dex and Con and get stuck with Savage Attacker (I think?) is some deeply interesting choice? Why? The narrative is cool, but the mechanics are
entirely awful. People just aren't going to do that because they don't want to be a level 1 Wizard with 15 Int. No, every Wizard is going to take whichever background has Int, and probably whichever background has Int and Con or Dex. The only way that doesn't happen is if War Caster is somehow an origin feat.
Like even if it was, "pick one attribute from your Class and one different attribute from your background. One of those attributes gets +2, the other gets +1."
I would rather they
eliminate level 1 ASIs entirely than continue to have them tied to species or background. Like if it's "too powerful" to always make the best choice, then isn't it just... allowing several too powerful choices?