There's a couple things you can try.  I'll note this question and answers are mostly a duplicate of [How should I respond to a DM who unfairly plays the “rules-lawyer” card?][1] though that one has a very slight 4e focus, you should review that extremely similar situation for guidance.

**Mirror Check**

First - general rule of Internet posts, is that when someone posts a rant about how a group is treating them unfairly, they are probably at least 50% of the problem.  If the group keeps yelling "GM over the book" at you, it is very likely that you are coming across as a bossy rules lawyer know it all.  I know you don't think you are, but because you're getting this response, you need to review what you're saying and how.  [Go read How does a player correct a GM mistake without being a rules lawyer or pushover?][2]  Also related, [How to handle a rule-lawyer player?][3] There's clearly a communication problem going on atop the actual problem.

**Try New Things.  Or Not.**

Second - try to figure out what the core of their play experience is, decide if you like it/want to try it, and do it. If not, leave, but I find that a lot of the discussion around play styles tries to pigeonhole people harder than alignment discussions do.  "Oh if you're a X type of player you will never like Y, run" is as poor advice as "You like heavy metal, you'll never like classical music, flee from your friend's orchestra invitation." It's only true for the small minded and obsessive fetishists. Is that a little harsh?  Sure, but only as harsh as "cocoon yourself only in the one game and game style you'll ever love and don't step outside it."  

In this case, maybe their playstyle is about the fictional game world and not the rules. Try looking for advantages *in game* - reasonable ways your character might get an advantage in combat in the game world, and then perhaps those lovely +1's will flow.  Watch how the other players interact with the world and GM and figure it out.

Sure, maybe they're just all dinks. That happens.  But also maybe this is an opportunity to try a new playstyle that is different from the usual Organized Play-centric groups out there.


  [1]: http://rpg.stackexchange.com/questions/16965/how-should-i-respond-to-a-dm-who-unfairly-plays-the-rules-lawyer-card
  [2]: http://rpg.stackexchange.com/questions/4317/how-does-a-player-correct-a-gm-mistake-without-being-a-rules-lawyer-or-pushover
  [3]: http://rpg.stackexchange.com/questions/158/how-to-handle-a-rule-lawyer-player