What part about "you do
NOT have to use floating ability score bonuses yourself" is unclear?
If someone does not want to use them, they can leave those bonuses exactly where they start out by default and it does not affect their gameplay or experience in any way at all. Your complaint is literally "someone else over there is having fun in a way I don't like so that should not be allowed."
This is basically saying, "You can choose to have suboptimal choices."
Not allowing floating score ASI's is saying "either make a cookie-cutter race-class-optimized choice which is exactly like every other character of that race-class combo or else you're forced into a suboptimal choice"
