Except that EY doesn't spend all his time (or even most of his time, I don't know) trying to solve impossible problems. He also blogs and helps organize conferences and stuff, right? All those other activities act as a hedge against him not accomplishing anything in FAI. Its not such a big deal to work on a problem that you never actually solve if your real career is as a writer/speaker and talking about the fact that you are working on this impossible problem is useful for that career.