Your statement of ‘hardly anyone considered facebook part of the web’ is incorrect. Facebook became popular a bit after the Web had become quite mainstream. The idea of signing up for online services was not foreign to most of these folks. Now, AOL/Compuserve and such were more considered as non web.
Yeah, those didn't count either. AOL and compuserve were not even available outside the USA in the late nineties. With AOL I'm quite sure nobody considered them to be a part of the web. Their pages didn't have URLs early on but AOL "keywords" instead. Compuserve also weren't using http I believe. It was some kind of commercial WAN that was pitched as a competitor to the internet, no?
Similarly Twitter; I signed up in I think 2007 and only used SMS for the next several years until they finally stopped it. Once I switched to the web/app version I was frankly appalled.