In fairness, I think many Christian churches would also object to such ads being posted in the immediate vicinity of their houses of worship. A few years back, the city bus stop shelter right next to the largest mosque in Manhattan sported a larger-than-life close-up of a woman wearing itsy bitsy bikini underpants. For many worshippers, this bus stop would not be reasonably avoidable. The poster mysteriously disappeared a week or so after it went up, and presumably wasn't removed by authorized personnel since the ad space then remained empty for some time. It is insensitive to put up ads like that in a place where it's guaranteed to offend a huge number of people. I expect the patrons of St. Patrick's Cathedral would have responded in a similar manner.
You're right, but I am not required to be fair.
Yeah but... Where are such billboards allowed in Saudi Arabia, for instance? Probably no where. It's a matter of creeping islamism: First it's offensive to the "congregation" (what a joke to refer to a bunch of these cutthroats as a congregation!) if the billboard is near a mosque. Then it's offensive if it's within eyesight of any muslim. Then it's offensive if it's anywhere in the country -- even if muslims can't see it. Then it's offensive if an infidel walks on muslim ground with his filthy feet.