Hunter's Point is no place for a stadium. It's miles from the nearest freeway and surrounded by the worst crime-infested neighborhoods in the city (not that Candlestick is any better). This plan would only work if coupled with a massive redevelopment and gentrification (er...
internal deportation) program for the area, which will provoke massive outrage from the usual suspects. The workable concept for a Mission Bay stadium site has apparently been given up since real estate values in the area have shot up much higher than anyone expected. Other than that, there is no other feasible site within the city limits. San Francisco is completely built out, so they have to destroy something to make this work. City Hall might be a good place to start. ;)
A lot of people in Santa Clara are unhappy about that site as well. As currently drawn up, it will amount to another big tax giveaway to an NFL owner.