This kind of word policing is even less OK. It's not "gross" to make a comment about something you see and have opinions about, especially for a public figure. You're not shedding light on any subject, either, all you're doing is being offended-on-behalf of someone else; the world's got enough of that and it doesn't seem to be making any positive difference at all.
I am not "policing" anything. I have no power to arrest someone or censor someone for being an asshole online. I expressed an opinion about the kind of community I'd like to be a part of. Also, it seems like you're doing what you're criticizing me for. I don't think the world's got enough of minding one's own damned business regarding people's health, body, and appearance, and that having more of it would make a positive difference. This conversation is about the science of fasting, not whether Jack Dorsey looks thin.
Sure, but only in a meta-sense to curb the proliferation of the technique. I'd liken it to nuking would-be nuclear powers to prevent further problems.
And maybe, _just maybe_, Jack Dorsey should eat a sandwich.
So, when you wrote this, did the idea of using nuclear weapons preemptively seem like an obviously good idea, to you?
There is a fascinating wikipedia article about this you should skim when you get the chance: https://en.wikipedia.org/wiki/Tu_quoque