That second part completely ruins the pithiness of the saying. It’s much better as just “I hate people who generalise.” Or, if you really feel the need to be explicit about the humour, “I hate people who generalise. All of them.”

Wow. The meta-ness of this humour almost defeated me, well played :D

Could have been the deadpan nature of the joke, or maybe it's just because I'm tired. Maybe it's because people correcting things badly because they fundamentally don't understand them is a pet peeve.

But maybe also because I don't recognise top-posted quotes as being part of the body of a work. Some how, my brain slots it into its own little area "this is simply context you need to know to understand the author's statement - not something the author wanted to communicate directly to you" - so by the time I had finished reading the quote, and the commentary on the quote, I had forgotten what the quote actually says.

I wonder if that's an argument for re-voicing square brackets - it forces you to read the quote in the voice of the author, maybe then my brain would treat the comment as a whole.