To be honest, pretty much all the experienced developers I met understood that. The "my silo and nothing else" kind of thinking tends to be something unexperienced people are more prone to.

"Consensus about any topic is impossible because political speech has become more polarized"

Yes -and- it isn't just political speech. Many developers naturally feel more comfortable with certain information sources (forums, blog posts, people, etc) and form self-reinforcing tribes around e.g. programming styles, languages, habits, editors, processes, and so on.