Exactly right. I am part of an acapella Church of Christ congregation, and when I was a teen, we were sent off to "singing school" to learn how to read music, to sing and to lead singing. Sure, there are exceptions, but most of the people I go to church with sing pretty well, because we've been trained, and we do it for a half-hour (at least) twice a week. I love it!
The very best musicians and singers you’ll find in church choirs and especially in the worship bands in the larger churches. But for the best singers out in the pews, look to the a capella churches.
Amen from a fellow dunkin' Campbellite! :-)