I like the way you have said it in your post, but have a question. How do you think ego plays into this? What about people who have an ego investment (but not an emotional investment) in their ideas? The times I've debated online, I often find a similar core dynamic (although different in surface style) with the majority of people in the debate regardless of how they are labeled. There are exceptions, but not enough consistency to make sense of the whole T-F spectrum.
edit: If you go to a T-dominant forum and start debating, notice how often there is an ego-investment in the idea even in the face of clear contradiction. There are people who are clear-thinking and admit when they are wrong, but they are precious rare. What I'm not clear on is whether or not those clear thinkers are a subset of MBTI-labeled T personalities, or if there is a mixed representation. Not long ago I read an Fe dominant's opinion where she stated that she was not entirely objective because of her experience, but still made a compelling case. It struck me how rare that kind of clarity is for a person to be able to self-identify their personal influences. People who have a self-identity of being objective sometimes struggle to admit their ego investment and that they have made a "stupid" error in their thinking.