It seems to me that the people getting the most pissed off are people who have no idea what a "go bag" is and live in the least likely places to need to have one.
I also think it is funny that lots and lots of people who have a low opinion of New Yorkers and believe New York City to be filled with horrible atheist depraved fornicating criminals suddenly think that the WTC site is "sacred".
To clarify; this building will be a mosque in the same way that a YMCA is a church.
It is a community center that will also have a place for worship. Mostly, it will be about things like basketball and after school programs and daycare, just like a YMCA.