A site I read on social skills has a post explaining why it doesn't use the words Introvert and Extrovert. The main points it gives are:
* There are no agreed upon definitions of the terms
* Just bringing up the terms can derail conversations and turn them into debate on what the words really mean (e.g., like what is happening in this thread)
* The terms cram too many sub-concepts into one
* False dichotomy
* Tends to ignore context (i.e., people act differently in different situations)
* Associated with a bitter Us vs. Them mentality
* The terms can make people feel defensive and closed off
* There are no agreed upon definitions of the terms
* Just bringing up the terms can derail conversations and turn them into debate on what the words really mean (e.g., like what is happening in this thread)
* The terms cram too many sub-concepts into one
* False dichotomy
* Tends to ignore context (i.e., people act differently in different situations)
* Associated with a bitter Us vs. Them mentality
* The terms can make people feel defensive and closed off
* The words can be self-limiting labels
Full post: http://www.succeedsocially.com/introversion