Life can take people to strange places, and because of it, I don't think everyone's PoLR is their worst weakness. I deal well enough with this PoLR of mine that it's been seen as 3D more often than PoLR by others, although my creative function sucks and that's because of my upbringing and suroundings.
The way I think, the way I act, and what I wish for are associated to different types, so I picked the one I think is most fitting of "cognitive functions" and went with it. I think that if everything about a person can be explained by something like socionics, there is a problem somewhere.