“Supposed to” doesn’t even figure in. To quite a very old saying, “You pays your nickle and takes your chance.” Now, whether an individual jellie reacts positively or negatively to a question has to do with a variety of factors including age, religious/political upbringing, nationality, interests, etc., but I would say that as a rule, most questions are acceptable, if not comment-inducing, to most members of this site.
Jellies who consider a question not acceptable can simply ignore or flag it. They can also jump into the thread and articulate their displeasure with the question, if they’re willing to entertain other opinions.
I myself ask questions about anything that interests me and/or have been unable to find answers in other ways that satisfy me. I use Google a lot, but being able to ask (or comment upon) a question among fellow jellies in real time is a great luxury and often generates one or more answers, or at least perspectives, that I usually find very helpful.