Personally I Think Paul Graham is very under appreciated, his legacy on the Startup ecosystem and zeitgeist will probably only be recognised many years on the future.
It's a great pity that he doesn't write these wonderful essays for some time now.
Read his book, Hackers and Painters. I don't think he's under appreciated. He was way ahead of the curve. And deserves to be happy with his family, or change the world some more..
I am sure he can console himself with the Scrooge McDuck like vault of money to swim in he must be able to build at this point, with all of the successful YC exits. Which the essays did a lot to create. He became tech world famous through his essays, which then gave him the clout to launch YCombinator.
(Are there public estimates of his current net worth?)