If you only get chump change, you do busy work. I agree in general that NASA should be doing bigger, more important things, but they're sort of resource constrained at the moment.
And, actually, you do figure out how to deal with long term issues in space by sticking up a metal can and orbiting earth for ten years. Yes, we could have done better, we could be doing better, but with the money and political power that exists, all you get is the ISS. Remember, space is hard. Really hard. The ISS has returned a lot of boring but important data on how people and materials survive in LEO. You don't get that data by watching Star Trek reruns.
And that 'fucking telescope' that has your panties in a bunch has a much better chance of significantly changing our world view than any reasonably feasible manned program.