are never really given a chance to become part of this community, they are labeled as “annoying” or something and regardless of what they do to change
Groups of people take on characteristics similar to individuals. While specific people within the group all deviate in certain respects, the group itself tends to take on an identifiable, individual character. (For example, think of "national characters:" the French are snobs, the Germans are militaristic and have no sense of humor, et cetera.) One way to classify people (and thus groups which have taken on a particular character) is by the permanence of their reaction.
* Some people have to have something proven to them every time
* Some people make up their mind and never change the opinion
* Some people make up their mind but can change their opinion if given a lot
of contrary evidence.
(For the sake of simplification since this is just a comment, I'll leave it at those three categories.)
As a whole, JU tends toward the second of those. In general, it makes its mind up quickly and holds to it. (Yes, there are always exceptions, but if you want to track the behavior the vast majority of the time, that's the JU zeitgeist as far as that goes.)
The very thing that gets defended on this site, freedom of speech,
I'd disagree with that. If you bring up "freedom of speech," what you are most likely to get is, "Freedom of speech only applies to the government. There is no right to freedom of speech here or in any other private setting!" That's the main current, the JU zeitgeist (again).
Nope, you won't find a lot of defending of freedom of speech on this site. (And while the JU zeitgeist is technically correct, I have a big problem with it.)
childish arguments ranging from insults, to name calling, to witty replies
You lump "witty replies" with childish arguments, insults, and name calling?
Okay, if you insist.