The frustrating things about how "ACTUALLY IT'S 'FREE SOFTWARE' NOT 'OPEN SOURCE' " has become synecdoche for a certain type of annoying programmer type is that, like,,
it IS a significant difference, sometimes! It IS often deliberately obscured how the main point of the movement was and should be Ensuring Freedoms, not just the side-point of "seeing the source code".
And the fact that the term Open Source was specifically created for businesses/marketing is... notable.