Tasha's was introduced as an optional rule.
A fuss over Wizards 'not doing enough' was raised in various online outlets.
Tasha's allows for any 'playability' solution you can get now, or in 5.5.
So why does Wizards remove racial ASI.
The answer has nothing to do with the game.
It's the same reason they are not going to specify heights and weights, the same reason they won't suggest alignment, the same reason they declare everything non-canon, and the same reason they put 'this product may not reflect our values' on old books.
None of this has anything to do with play.
It is Wizards saying 'you can't blame us, talk to your DM!'
I had a thought today that this is more of a shift of how players create characters.
Back in the day, human was seen as default. You sit down, and you create a fighter, or a wizard, or a cleric, and then if you wanted to specialize further you played a non-human race, accepting that you were penalized in some way (ability score penalty, class restrictions, etc).
3e really changed the dynamic by allowing any race to be any class. Suddenly you could have a half-orc wizard, though you still were penalized with an ability score penalty.
4e shifted even further my removing ability score penalties.
Over time, I feel like the idea of "human = default" has become, well, old-fashioned. It's no longer the way many groups play. But it's still embedded in the rules by pairing nonhuman races with ability score improvements.
These days, I believe a lot of players want to choose a race based on their character concept, not necessarily to specialize. When a player chooses to play a wizard, they don't necessarily default to "human wizard." Instead, they might imagine a half-orc wizard, or a halfling wizard, or what have you.
WotC's recent shifts seem to support this trend, and I think it's one of the things motivating these changes.
