Am I just falling for communist propaganda... or do they have some valid criticisms of capitalism?

Like for instance, what happens once we've sucked all of these resources out of the Earth? Then what? Aren't Earth's resources finite? Won't we run out of resources this way? And what about capitalism greatly empowering coorporations that end up manipulating governments? Does the end justify the means and is corruption just a part of capitalism we should accept and learn to deal with?