I feel like you are trying to paint it as a shibboleth because you feel targeted by it or you dislike the ideology of people who use it but it's probably just a banal reaction to the "doomer" adjective that I have heard before it and is even more entrenched

It just makes sense that the bigger the agora in which a debate takes place, the more nuances will fade away until you can roughly sort people into the "X bad" and "X good" buckets. Is it desirable ? I don't know. Is it some group's lobbying/conspiracy ? I don't think so