I have never understood this "can't put people in boxes" thing.
Watch me put everyone in one box: every one of those 7 billion people is a human. Not only was that not impossible, it was easy.
If all it is is a damn good heuristic that can make people think more clearly about how other people think, I'm totally ok with that.
All of this is true.
We can create a bunch of different boxes and draw lines anywhere we want. The thing we've gotta ask is how descriptive (and thus how
useful) our boxes are.
Mashing all 7 billion people into one box separates us from the monkeys--bam, in fact, that's what the whole field of
taxonomy does. But it doesn't help us understand within the realm of
people any better; and so if that's our aim we've gotta try something else.
Thus, we have our typologies. To the extent that, say, MBTI helps make people think more clearly about how people think, it's a great thing. Knowing the limitations of the theory, though--that it's more of a heuristic than an absolute, or that it doesn't describe behavior unless one reaches
way to far--is part of understanding the theory.
The people who develop theories should take on some of the burden of putting their theories in proper context, but they also can't help much if others misuse them.
In short, I'm in total agreement.