The personalities of some wuxia characters is pretty bizarre by real world standards, but there are also plenty of wuxia characters whose personalities aren't too different from those we commonly see in real life.

What common personality types in the real world, however, are conspicuously missing from wuxia fiction?

I think the procrastinator/flake that is so common in real life is pretty much unknown in wuxia fiction. Everybody in wuxia seems so earnest and committed to whatever it is they're committed to. Nobody seems to have that, "Meh...that's boring...I'll do it tomorrow" attitude that's so common today.