I remember back in the day I had a demo disc where one of the installers (I think it was Theme Park?) had a prompt of "Press return to quit, press enter to continue". And that confused single-digit-years me for a surprising amount of time, as there wasn't, to my mind, a real difference between the two keys.
Even then I assume it was really a troll as much as anything else.
My experience is with IBM AT and OS 2 which had a Return and a numpad with an Enter. The AT and Model M keyboard at least were part of a very popular and influential generation or two of "PC".
Even then I assume it was really a troll as much as anything else.