Chalicechick and Jeff at Transient and Permanent are both talking about how UUs make distinctions between "birthright" UUs and "come-outers" and the assumption that people not born into the church are sometimes thought of as bitter refugees from their original tradition.
To me this is a lot like our language around "crusty" humanists. I belong to a small fellowship movement heritage lay led congregation. (Readers playing the home game can try to guess from the picture I posted before)
In my congregation there is a spread of secular atheists, new age, Vedanta, Buddhist, Christian and pagan members. (think two or three of each really). People do nice lay led sermons about what was good about their family traditions or something they really liked about Catholicism. They also do sermons on Hinduism, Buddhism or other world religions. No one bats an eye if I read from the Revised Common Lectionary one week or someone talks about Yom Kippur and atonement. We also have our share of what I would consider lectures about different topics. But all told, it is pretty well balanced.
I don't think we do a good enough job of including our pagan members. And I think we are a little hesitant to try new liturgical elements or to constrain the time taken by Joys and Concerns on any given Sunday.
I know that our stereotypes exist for a reason, but I think we often let a small number of cranky individuals give us the wrong idea. And again, it is a reason why I think the notion of The Tyranny of Structurelessness is important. If we do not use structures to facilitate participation and access, the loudest and most privileged will always win out.