This is from the main site:
9-11 Survivor is a game project that examines the role of media in our culture, and the influence that continuous, hyper exposure has on our overall perception of the distinctions between reality and media mediation. This project raises questions regarding how and why popular media forms, such as games and movies, deal with tragedy, conflict and violence.
Perhaps they really do have legitimate reasons for this project...
They might be examining how people can play extremely violent games that revolve around hurting and killing other people and yet remain indifferent to the violence. They could be trying to understand how and when violence and killing becomes "fun" or acceptable.
Basing a game on the terrorist attacks of September 11th brings the violence and death much closer to the player, forcing them to really think about what they're doing. In a way, this game is similar to many other violent games that attempt to be realistic, like Counter-Strike, except it removes the distance between the player and the game world drastically.
Is this game tasteless because it's about innocent people dying, or is it really because the event actually happened and occured very recently? I would tend to believe the latter, since we play games based on the world wars, Korea, Vietnam, and even the 1993 conflicts in Somalia. So by playing the aforementioned games, does that make us hypocritical for calling this particular game tasteless?