Money. It costs a lot of money to run NASA. All of it has been going to the ISS, which is really to bad. We should have left low earth orbiting space stations to the Russians.
If going to the moon had direct commercial value, private industry would have gone there decades ago. Unfortuantely, it dosen't seem to have anything we need that we can't get on earth a whole lot cheaper.
it doesn't seem to have anything we need Whaddya mean? Everyone knows the Moon is made of green cheese. We could lessen our dependence on French cheese by importing Moon cheese. Sell it wrapped in tin foil for the conspiracy theorists.