Not compared to the stupid and delusional Jesus claim. I don't go into a church and tell them they are all nuts either. And i bet you don't either.
Why do insist on being rude to others? Seriously, why? You're life only has value if you make someone else miserable?
You apparently didn't read, or you entirely disbelieve, what I've already written. While you're advocating politeness and respecting what people tell you about themselves. If I said I was trans, you'd agree (while privately knowing that it's "stupid and deluded"), but the things I do tell you, you ignore.
Also, my experience isn't that they would chastize you. They would correct you. If you deliberately continued to misgender them they would ignore you.
That's useful to be reminded of. They just don't include you in their friend group if you don't play along. No harm done. Did all your trans friends know you thought they were "stupid and deluded", by the way?
And of course the claim your gender is the opposite of your sex isn't as silly as my claim that I'm "Jesus Christ", but that was the point. A humorous, exaggerated example of delusion you might encounter, a thought experiment, to see if there are examples where you
would challenge someone. It wasn't a good choice. Clearly I'd be so bonkers there'd be little reason to challenge me unless you saw me dragging a large cross up a hill. Would you then? Probably not. No skin off your nose if I think I'm Jesus and get a few mates to nail me to a cross, eh?
Say a friend claimed they were a feral dog, and started sleeping out on the streets. Would you just accept that, pat them, feed them treats, teach them tricks, and walk them on a leash? (Exaggerated, unlikely example, remember - this is a thought experiment only.) Can you comprehend the principle of EVER challenging someone being "stupid and deluded"? That's the point.
The point of it is to see if you're able to think. The point is to see if you can begin to understand those people who are concerned about just playing along with delusions (some, like me, so concerned that we've decided not to if we can). You would then, of course, have to begin to consider whether their concerns had any merit as well to begin to see me as anything but someone who likes to be rude to people to big myself up. But no, all you'll do is ignore (or twist) everything to look like you're right, whatever it takes, and the other is wrong. This is intellectual cowardice.
You're so determined not to think, you pretend you don't understand the meaning of "Jesus Christ" when put to you, instead pretending you accept that I am called Jesus, which is a common name. Problem solved. Nothing to see here.