Or... maybe I'm just trying to rationalize my disappointment with that forum...
Yes, I think that's where you're going.
The INTJ's on the forum, while they are the same personality type, do have very diverse views, and do get into a lot of arguments. But the agreement and "ego-stroking" (not sure what you are referring to) are probably just the result of the INTJ's appreciating that the other INTJ's are thinking in the same way. In the debates I have had on the forum, I have of course had major disagreements in terms of fundamental stances, but I have usual seen that the other INTJ has thought something through rationally, and is actively thinking about my arguments, presenting well-conceived responses. That results in a large number of "respectful disagreements," relatively untainted by emotional reactions.
What causes your "disappointment" with the forum? Do you think it's much better here? I don't see much a difference, except that INTJ Forum has a faster server and a bit more traffic.
I guess I feel pretty at home there. It is something of a "comfort zone," where the people tend to think the way I do, avoiding absolutely foreign opinions. They have good insights, presented in ways that make sense to me, and I find the selection of threads suits me quite well.
I think of MBTI Central as the "lab," or something like that. I come here to get fresh opinions, and see what the other types think. It is a bit less inviting (though perhaps that is just because I am not very used to it), but it is also a nice change of pace if I am especially curious about the perspective of another type.