He also made a pile of money on Mathematica. I'll give him that as well. It was classic "solve your own problem" entrepreneurship. He needed a better computer algebra program, so he wrote one, then started selling it.[1]
But he's a crank. He wrote a couple good papers in the 80s, then hasn't done anything decent since. He published A New Kind Of Science in 2002, which was supposed to change the world; except that half of it was nonsense and the other half was stolen from other people. (http://www.cscs.umich.edu/~crshalizi/reviews/wolfram/)
Feynnman (kinda) calls him out on this: Complexity research doesn't need its own institute, because complexity research is a pseudoscience that means whatever you want it to mean, like how the homepathy quacks have latched on to the word "quantum".
1: Wolfram Alpha is the same thing. Wolfram wanted a natural language parser, so he wrote one. Except it doesn't work worth a damn, because natural language parsing is a hideously difficult problem, which probably requires strong AI.