It's both. Trendiness in this case arises from two things, very broadly:

1. A threshold (you can't just keep doing more of something without a reaction eventually, once enough people are made more aware of the related issue). This part relates to the community cost of data centers.

2. A difference (they now facilitate AI, which has a popular image of stealing human effort and eliminating jobs, and, subjectively, being obnoxious).

So yes, there is some trendiness, but there are also concrete issues from which it is derived. It can't be dismissed as purely "trendy" in the "not rational/holistic" sense.