Dear Michael, [talking to myself as usual] I noticed that you complain about incompetent people. When I hear that I tend to put you in the category “egomaniac”. What can we do about that?
Sounds much nicer than: “Michael, you are an egomaniac. I know that because you complain about incompetent people” doesn't it?
Even if you're convinced that the other Person (or team for that matter) is malicious, unhelpfull or in any other way “bad” remember that that's just the way you perceive it. Talk about yourself – that is something you can be sure about and that can't be argued away. [It is very hard to tell somebody “no, you do not feel that way” – although sometimes there are people who try.]