This is basically "heritage not hate" but for a socially-acceptable target. You're saying racist opinions are fine as long as you don't act racist.

The stigma causes the hate, they're effectively the same thing (I used them interchangeably) and leads directly to adverse actions against those individuals.

And the argument generally shifts at that point to "it's good for them to be attacked, maybe it'll motivate them". Because again, it's just a socially-acceptable vector for hate. We've gradually run out of other forms like racism and sexism, for a while it was homophobia (and the argument was that was a choice too, so it was fine to attack), but we'll always have fat people.