It is also possible, that the illness gave him the fanatism required to maintain the focus over the years, to come so far with TempleOS.
(That same fanatism and crazieness also prevented people from participating I guess.)
I bet it was less about fanaticism and more about time. Previously, he had worked full time and made money. He wasn't able to work after the illness (I think I read somewhere that he was rehired by his old company, but only lasted a few weeks).