I am sure that many people have no idea how far their denominational teachings stray from the Bible. BUT, I know some people who admit that they DO know, but choose to stay in the denomination. I even know of church leaders who have signed statements of belief that they know to be unscriptural...
We meet on a Sunday because that is still the most convenient day for most (but not all) people to do so. If we had to meet on, say, a Wednesday evening, it would not bother me at all.