[anorakoverflow]

The problem with scientific terminology is widely recognised in communication science. The issue is that while terms used by disciplines such as physics, law or medicine are sufficiently esoteric that someone “on the outside” wouldn’t use their terms casually, so they are somewhat protected from “watering down” their concepts in public discourse—or not, as we are seeing with anti-vax ideology, for instance. Terms in communication science also carry specific meaning to those who know them, but can just as well be interpreted as everyday language by outsiders.

I also get what you mean by “straw-man-y”. I think the issue is that definitions have to be robust and hypotheses falsifiable in order to make them researchable, so they must be kind of stringent. Exactly as you say, someone might be in a political echo chamber, but that is not their entire life. They have peers, family, friends, colleagues that also expose them to political information. By focusing so much on the online, the echo chamber assumption was very limited from the start.