This topic has stirred up some emotions and philosophizing. Good stuff.
Building a mosque - an extravagant mosque - at Ground Zero will undoubtedly elicit an emotional response. I was there that day; two blocks away. I saw Tower 2 begin to collapse. I ran. I was caught in the cloud. I thought I was going to die. I spent the day trying to get out of NY. I spent the following weeks coping with the event; seeing posters and flyers searching for the dead; remembering the dead. I passed a fire house everyday with flower wreaths and photos of the deceased firemen. I understand the emotional reaction.
But intellectually I can't associate this act with Muslims. No more than I can associate bombings in Northern Ireland with Catholics or Protestants. When acts of violence are justified by religious affiliation I immediately separate the religion from the act. Violence is an act of deviance; of pathology. Extremists. Don't put a religion after or before that word.
I suppose that legally a mosque can be built near Ground Zero, but it shouldn't be built. The entire area should be declared a cemetery. The remains of hundreds or thousands of people are scattered in the ground of that site. Leave it be. Plant grass and trees and let it be a memorial for all who died there; Muslim, Christian, Jew, Atheist....human.