Ok I admit it. I have sometimes been rude to other players at the poker table, mostly online. There is no excuse for this behavior and I am glad to say that I have managed to quit. There are several reasons why you should avoid insulting your fellow poker players, apart from the fact that it is just not a very nice thing to do.
Your opponents draw out on you with a backdoor flush and you curse him out calling him a fish. But why? You want him to chase and call you against the odds. He will outdraw you sometimes, but you will prosper in the long run. If you are rude he might leave the table, and you don’t want that or otherwise change his behavior, and you don’t want that either. By being a bully you risk affecting your opponents’ game to the better, which is just plain stupid. By working yourself up and cursing other players I also find that you increase the risk of going on tilt and you tell your opponents that you are not a very stable player. Next time someone hit that two outer, just take a deep breath and remember that the fact that he did is good for you in the long run.

Roy Cooke wrote an excellent column on this subject in Card Player. If you recognize the behavior described above you should definitely check it out.