My opinion on that: INTPc is a forum with like 2200 active members. The cultural, educational, personal, etc. differences would already form a multitude of characters, and let's not forget that the type is related mainly with tendencies and preferences, not with behaviour. Even between INTPs some might be more extroverted than others, some more feeling, some more detail-oriented, etc. and, in all cases, the personality is much more than 4 letters, in my opinion.
As for the reactions towards members of different types, I think most of them are purely humorous, with intention to jest, not to insult.
Of course the phenomenon of members trying to fit the stereotype is present in many cases, but I find that mostly the younger members tend to do this, by younger meaning both in age and in having discovered their type. I think it deserves the way to try not to feel offended by the most immature members and focus on discussions that might really offer some interesting point of view.