To say that "people were just hanging out with him because he was rich" is a very biased and uncharitable reading of his biography. He gave away all his inheritance pretty early in his life and later often had to depend on friends such as Keynes, Russell and Moore to support applications for grants so that he could continue his research at Cambridge. Of course it's true that he came from an extremely privileged background and was never in danger of starving to death, but he could spend as much time on his philosophy as he did because he lived a modest life and was lucky enough to be supported by Russell when he first came to Cambridge.