If someone had posted a question asking how to end an unresponsive ssh session, perhaps RTFM would be an appropriate response. In this case someone is sharing knowledge that could be useful to many people. Just because something is written in a man page, does that mean it should be locked away to only those intrepid enough to read the man pages of every tool they use? Community curated knowledge is useful.

As well, I'm not sure if you're intending to, but you're coming off as an elitist asshole. Not knowing an esoteric bit of what is essentially ssh trivia does not make someone a neophyte. For anyone who entered the field in the past 15-20 years, hitting the (x) close window/tab button is likely more second nature than 'enter ~ .' Please don't be like the guy who hangs out in IRC help channels just to tell people wanting help to RTFM.

Being a shaming douche doesn't help people--it hurts them. Some react in an in-the-end-positive method because they are hurt by people like you--they develop scar tissue to inure themselves against your consciously-adopted sociopathy. Most say "fuck it, I won't deal with these people", throw their hands up, and leave. It's toxic behavior and it is unacceptable because they are more desirable people to have in a community than people who glorify the shaming of people who don't know obscurities.

Be a better person.