Psychology has many valuable points, but then why not just accept that human interaction is subjective rather than label persons as introverts and extraverts?
lumping people into general groups with general preferences does not mean that psychologists do not appreciate the subjectivity of human psychology.
"all models are wrong, but some are useful"
~George E.P. Box
ENFP: We put the Fi in Fire
Motivation: Dark Worker
Alignment: Chaotic Neutral
MTG Color: black/red
Male Archtype: King/Lover
"You are a gay version of Gambit" Speed Gavroche
"I wish that I could be affected by any hate, but I can't, cuz I just get affected by the bank" Chamillionaire
Extraversion and introversion have been connected to differences in brain physiology. Yes, it's still all on a continuum, but there are actual physical differences, which are worth understanding and documenting.
Hope is the denial of reality. It is the carrot dangled before the draft horse to keep him plodding along in a vain attempt to reach it. We should remove the carrot and walk forward with our eyes open. -- Raistlin Majere