Why does Ground Zero have anything to do with Islam?

I’ve heard the debate raging around the so-called “ground zero mosque” the last couple of weeks, and I see a lot of confusion as to why Islam is in the argument at all.  Pundits say invoking Islam as a reason to stop the development of the center is simply “Islamophobia”, and that a center founded by Muslims built in downtown Manhattan is fully in accordance with the freedom of religion inherently built into our constitution.  Or, conversely, they attempt to disassociate Islam completely from ground zero with statements [...]