Any relative lack of notability vs. the others HN has black-barred was because he died so young. Think of all the things he likely would have done over the next 60 years if he slowed down even 50%.
I only raise the question because you say the opposite, and in such situations the absolutely worst thing the community can do is canonize someone, exaggerating their accomplishments and raising their words above actual merit (the front-page is full of his old entries now. Why?)
I suspect that Aaron's curse -- the thing that made a very privileged Western existence "too painful" as others have said -- is that he peaked so early. He did the right things at the right times with the right people, and while he was clearly a very bright individual, I think that ended up becoming baggage that dragged him down, every future effort unlikely to ever shine as bright.