In these circles, yeah, maaaaaybe introverts are the majority.
For the general population? No way. Most studies put the number of introverts somewhere between 20-40%.
Extroverts are loud and they are the majority, too.
As someone on this forum put it, the only evolutionary advantage to being an introvert is that you're insurance in case all the bunched up introverts die in a natural disaster, while you're away sitting alone in your far away corner.
Majority rule :-)