It can be difficult to be an introvert in church, especially if you happen to be the pastor. Liking to be alone can be interpreted as a judgment on other people's company. Liking to be quiet can be construed as aloofness. There is so much emphasis on community in most congregations that anyone who does not participate risks being labeled a loner.
You can create an intimate community of about 20 or 25 people, and beyond that you're into a different kind of relationship.
The tradition piece is so embedded in me I don't know that I can see it any more, but the community piece is one I've been in danger of losing.
To be in the mainline is to have a history and not simply to be an amalgam, a community church of who knows what that came from who knows where.