My dude, if shaming worked I'd be a size 0 from my Korean grandmother's words alone.

Pick one of your flaws, let's say making shitty comparisons. If everyone were to persistently shame you for your terrible analogies, would you feel inclined to change your behavior or would you get defensive and beligerent? Of course you'd like to think you'd do the former, but in my many (many, because I'm old) years of experience, most people do not. Most people, when confronted with their deepest, most shameful flaws, get very defensive and sometimes go so far as to double down on that behavior.

Being fat is a flaw. No one is arguing that. But everyone has flaws, it's just that for non fat people, their flaws are often less discernible and not out in the open for everyone to feel entitled to comment upon. If everyone's flaws were as visible as being fat and we all decided it was open season on shaming, what kind of world would that be?

My point is, how about we be kind to one another? We never truly know what's going underneath it all, so why not live and let live?