Churches historically have provided their buildings for weddings and funerals. Sometimes its because its the largest building around; sometimes its because the church also maintains the cemetery.
In any case religion of all types have been the ones to "bless" a wedding. Religion certainly aims to provide comfort and direction at a funeral. It is nearly universal that religion enters a persons live at the beginning and the end.
Our church has provided facilities for funerals at the request of the family or city government (public safety issues). We provide a lot of services, even as a private organization, that we do not charge for. Its part of being a church, at least for traditionalists.
I could not imagine that a Jew, Muslim or Wiccan would be comfortable at a church for a wedding or a funeral. I cannot imagine that a traditional church would open itself up to other religions, but it might if the circumstances warranted it.
Huh, it just never occurred to me that people would expect a church to provide services to just any person... Seems strange to me.