The "downvotes magnet" thing was tongue-in-cheek – any name is either not famous enough, making it a bad answer, or famous enough to have lots of fans that will disapprove of the nomination.

> why Kay?

I don't think his actual, lasting influences justify the near-mythical status bestowed on him by his disciples. Not saying he's completely unimportant, just that he's overrated. I'm not very confident on that assessment though, which is why I listed him last (and ESR first).

Alan Kay was the idea man. He situated Smalltalk in a context of, this is programming as media, as a form of expression and a means to learn and teach, and not just an engineering activity; when it comes to Smalltalk, Dan Ingalls did much of the implementation work.