(Note, I came to this conclusion after reading about a bunch of his technical accomplishments, which I can see are awesome, even if the obvious megalomania evidently occasionally dampens their effects.
I think his work is fantastic, his politics are largely reasonable - but I think his self-obsession is often the driver behind a large amount of damaging and counterproductive behaviour.
Politics is the art of compromise - not convincing everybody you're a saint while alienating your natural allies.)