It is a shame what happened to Sim later on. Particularly because his extremist views, and hostile stance in defending them (if you don't agree with him then you're part of the so-called "feminist-homosexualist axis"), have overshadowed his earlier, brilliant and genuinely innovative work. Not to mention his pioneering role in comics self-publishing and creators' rights. Nowadays, when Sim's name is mentioned online, it's nearly always in a "that crazy guy who published rambling misogynist tracts disguised as comics" way, often by people who've never actually read a single page of (earlier, good) Cerebus. When Frank Miller's name comes up online for the usual "whoreswhoreswhores" treatment, there are at least a few people who'll remind everyone that he used to put out not just good but groundbreaking work. But rarely (outside of s_d 1.0 and 2.0) does Sim's earlier output get any defence.
Of course, Sim has no one to blame for his hateful crank reputation but himself, but it's still very sad to think that after his death he'll be remembered as a reclusive fanatic and nothing else.