Earlier quoted context omitted.
Nobody follows Kay's definition of OOP. And I bet you're going to say "But he coined the term!". Yes. He's still making up his own definition twenty years after the industry gave its own, so whatever he says on the topic is moot.
Several things to note here. Firstly, I don't know at what exact point did Kay come out in demystifying OO (1998 or so?), but the design principles of Smalltalk and messaging date back to publishing in 1974, with many references to it afterwards. Secondly, the idea that there is one singular definition of OO that the industry has standardized on is absurd. Object models differ semantically from language to language,…
That's interesting because Armstrong himself thinks that OO sucks:
http://harmful.cat-v.org/software/OO_programming/why_oo_suck...