The point isn't that it's restrictive, the point is that words have precise technical meanings that are the same across authors, speakers, and time. It's rigorous because of that precision and consistency, not just because it's restrictive. It's necessary to be rigorous with use of language in scientific fields where clear communication is difficult but important to get right due to the complexity of the ideas at play.

My comment doesn't suggest people have to run their own research study or develop their own treatise on every topic. It suggests people have make a conscious choice, preferably with reasonable judgment, about which sources to trust and to develop a lay understanding of the argument or conclusion they're repeating. Otherwise you end up with people on the left and right reflexively saying "communism bad" or "capitalism bad" because their social media environment repeats it a lot, but they'd be hard pressed to give even a loosly representative definition of either.