Robin Hanson wrote about a relevant phenomenon in Why Signals Are Shallow:

We all want to affiliate with high status people, but since status is about common distant perceptions of quality, we often care more about what distant observers would think about our associates than about how we privately evaluate them.

Thus, people can genuinely dislike their allies having an activity that gives shallow negative impression (feel the dislike, not just deem the activity a mistake), even if they understand this first impression to be incorrect, or that any person giving a minute's thought to the question will come to the same conclusion.