Bore, your perspective is from the milquetoast Church of England people in a country where evangelism is generally seen as distasteful. We have a rather different perspective in the good ol' USA.
I've never been so mortally offended in my life. I'm Scottish
But yeah, like I said I don't know enough about the charity situation in the US to really comment on it. Like all sane people I find the vast majority of American Christianity awful. What I would say is the homelessness work which I'm really familiar with is done by various branches of Catholicism, and they don't discriminate or evangelise, so I'd assume that at least a good proportion of church charity projects in America are non discriminatory and non evangelistic.