There is a learning curve with anything, and using Stack is no exception.
Stack Overflow, (and the Stack Network of Q&A sites in general) are community-moderated, and I don't just mean via the users with diamonds next to their names. Your reputation (the number on your usercard), represents, well, your reputation - it's a small measure of how much the community trusts a particular user, because questions they've asked and answers they've written have been upvoted. (There are other sources of reputation points, but these are the most common).
As you earn reputation (or 'rep'), you will unlock privileges to use and moderate the site yourself. At 50 rep points, for example, you will be able to leave comments under other people's questions and answers. This is because comments are meant for requesting clarification of a question or answer, not for general chat or 'thanks!' style comments, so it was decided that people who've stuck around long enough to earn 50 rep points (5 upvotes on answers, 10 on questions, or some mix of both) would generally know how to use them.
And as you go up the privileges chain, and we trust you more and more, you'll get access to more 'dangerous' tools, like closing and deleting other people's questions. Generally, by the time you access these tools, you've got a fair idea of the policies of the site and what we're about.
But why do I bring all this up? Because a lot of people that visit the Stack sites assume that we just accept any old question and answer. They're only here to have their question answered, why should they care about the mods, the site, the community? They need an answer, dammit!
What inevitably happens, is that their question gets closed (or their 'answer' deleted), and they get frustrated because they "only came here for an answer" or "it's obvious you don't want my help".
You see, the thing is, Stack Overflow (and the network sites) aren't just trying to be 'any old Q&A site':
Stack Overflow is a question and answer site for professional and enthusiast programmers. It's built and run by you as part of the Stack Exchange network of Q&A sites. With your help, we're working together to build a library of detailed answers to every question about programming.
- Stack Overflow's Tour
We want our questions and answers to be helpful to more than one person. We strive for questions that are useful, answerable, on-topic and to-the point. It's why
- Open-ended topics
- Questions which are chatty or trivial
- And blatantly off topic questions
- "How do I install a new graphics card?"
are regularly closed and deleted (or potentially migrated to another site RE: the latter one)
As time went on, we discovered other 'problem' topic areas, and started removing questions about those too. On Stack Overflow, that is:
- Questions you haven't tried to find an answer for (show your work!)
- Product or service recommendations or comparisons
- Requests for lists of things, polls, opinions, discussions, etc.
- Anything not directly related to writing computer programs
- Stack Overflow's Tour
However, we also
- Edit posts we deem salvageable
- Flag problem posts and comments for review (Spam, Rude/Offensive, Not An Answer, Low Quality, Off-topic etc)
- Reopen questions which the asker or others have clarified
- Constantly clarify our policies on the site-specific meta sites (this meta site is for the entire network)
- Close and point askers to duplicates that solve their problem (Dupes aren't bad!)
All these things we do (and more) in the betterment of the sites (and the world!) in general.
But back to the topic of 'cliques' you were talking about: Does doing any of the above make us a 'clique'? Maybe to people who don't know why we do those things, but I can assure you that it is not by some secret design or 'clubhouse' rules. We try to be as welcoming as possible.
I won't say that you wont come across groups of 'friendships' here, nor will you agree with each and every user you come across. However friendships are just that: friendships - they don't influence the site at large (and if they did, they would be a small bubble in a large ocean, and would be overruled when necessary). If any conversation turns uncivil, all you have to do is flag for a diamond moderator's attention and walk away. Behaviour like that is strictly not tolerated.
Anyway, if you read all that without getting bored, then welcome to Stack Overflow! (and Network Sites/Stack Exchange/whatever we're calling ourselves now :) )