Henry is literally blacking out and has no control over what he is writing. He’s trying to show them that he’s working on it, on fixing a problem that Hook is the cause of in the first place and all Hook (and Emma and Regina) can do is criticize that he’s, essentially, not working faster to save them while Emma and Hook spend the entire episode sitting in the apartment doing absolutely nothing to help. It’s not just what he says; listen to how he says it: sarcastically, rudely, and with an air of frustration and disappointment. Yeah you’re stuck in Hell, Hook. That must suck. But you’ve placed all your hopes of getting home on the shoulders of a 13 yr old and when it turns out he can’t work to your level of satisfaction…then he gets to be mean and no one calls him on it, instead they all blame Henry’s “teenage” disposition. Like, are you kidding me? He’s literally blacking out.
add in the latest sneak peek where once again Hook is being snarky/sassy lines that more or less “make fun of” the magical solution people are trying to come up with to get them all home–something that again is Hook and Emma’s fault–and it’s really unnecessary and cruel. He’s being incredibly ungrateful because it comes across as “how dare you have not saved me yet!