The phrase "gay people are gay" is a self-explanatory tautology, as well as a paradoxical statement. Gay people technically are gay, but at the same time the pejorative use of gay also leads some very sensitive people to conclude the opposite. Hence, it's paradoxical.
A funny thing in middle school where someone would ask you if you have seen the clown that's hides from.. You know. Gay People. And if you say no... Well.. your gay then.