Think back on him historically. Remember the stories of him making thermite to steal school computers or literally demolishing walls in the ID office so he could see everyone all the time? They become much less "oh quirky guy" and more "oh, small business entrepreneurial freak" when you put them in the context of him stealing those computers for his business and demolishing office walls so he can oversee all his workers 100% of the time. All of his historically shit behaviour has been excused because "he's the doom guy" and he's ridden along on that "quirky" aesthetic, but the truth is he's an absolute shit.
If you want to remember someone for Doom, John Romero is the cool one.
Damn, that's sad. Didn't know much else about him other than the genius behind the algorithm, why must so many people turn out to be complete asshats...