I love your counter examples. In moving beyond the famous Shannon-Weaver model of communication[1], the one with the "signal," "noise," "channel" that network folks love, researchers settled on the importance of "feedback." I would say that these popular stories that become part of "mainstream culture" spread through comedy, song, news, bars, and repeated viewings on television to reinforce and strengthen the "mainstream" understanding of what these things mean and whether nuance is important when talking about them.
[1]: https://en.wikipedia.org/wiki/Shannon–Weaver_model