Why is introversion a disorder but not extroversion?

[Beery]

It's the dictatorship of the majority. Most people are extroverts, so they get to decide that their way is 'normal' and everyone else is 'abnormal'. In my view, the extroverts are the crazies - they desperately need human contact, and if they don't get it, they act out, get depressed, some even kill themselves or others.

We're independent, fully complete individuals. They have an inherent socio-psycho-pathological deficiency that can only be filled by others.