I sort of agree. I didn't treat this issue because the post was already getting too long.

We have various incentives to want obese people to become thin: paternalistic concern for their health, negative externalities, selfish reasons if we're their friend or relative and want to continue to enjoy their company without them dying early, aesthetic reasons, the emotional drain of offering them sympathy if we don't think they deserve it. One of the most important reasons is helping them overcome akrasia - if they want to become thinner, us being seen to condemn obesity might help them.

If they don't want to become thinner, that incentive goes away. The other incentives might or might not be enough to move us on their own.

(usually, though, these things only become issues at the societal level. I can't think of the last time I personally was mean to an obese person, despite having ample opportunities. In that context, I think the feelings of particular obese people on the issue becomes less important)