Such a great thread.
Instead of being called introverted how about: socially selective?
I spent so many years around people who could not talk about or get excited about or relate to writing and other passions of mine and I know I was starving my soul bit by bit.
I also think being exposed to certain people can kill my inspiration to write, and the quality of my writing whether or not I discuss it with them. Inspiration needs a certain environment to surface.
Don't get me wrong, I am entertained by extreme personalities and they will show up as my characters, in fact I love eavesdropping at airports and restaurants and bars.
But if wishes were horses I'd surround myself with creative, sensitive open minded people. Until that commune is founded I will stay home.