The "haters are fanboys except for one thing" idea is useful and I think accurate, though not particularly original. The rest reads like a longer subtweet. It makes me wonder which particular hater(s) pg is hating on.

That said, there is one other aspect worth commenting on: the "nearly successful" kind of hater. Yes, they absolutely exist. Academe is particularly full of them. The reason, I think, is simple: some people resent those they compete with. For that kind of person, that means the people right next to them in whatever real or imagined ranking. Those further above or below are irrelevant, and not worth hating.

The other key (subtweeting a bit myself here) is that some people invite this particular kind of hate. They exaggerate any difference between themselves and those they have barely outdone. They hotly deny the role of luck or privilege in achieving their status, more often than pg seems (or wants) to think. Psychologically, they mirror others' envy with a desire to reaffirm their position in a race they know could have gone either way. There's a bond between the haters and the hated, and often both sides participate.