Too controversial?

This is just weird.

NEW YORK (CNN) -- An advertisement from a U.S. mainline Protestant denomination calling for the inclusion of gay men and lesbians in church life has been rejected by television networks CBS, ABC and NBC.

CBS and NBC said the spot violates their policies against running ads that take positions on matters of public controversy.

"Matters of public controversy?" I seem to recall seeing an advertisement or two recently that had something to do with who should be the next President of the United States. And why is inviting people to church controversial anyway?