Less of a “tribal” aspect for my experience and more of a “shared personal preference”. I work for the shop that is rare in the world, which has both Trek & Specialized actively sold at present. We also hold a bit of history as dealers for both that reach back nearly the full term of their existence.
We have a share of people who are partial to one brand or the other. I say it’s not really “tribal” here because it’s less “us vs them” and more about what people have ridden and prefer. Sure, there are some haters with whatever reasons they hold, but it’s not monolithic in my experience.
For my own history, I used to be a hardcore S guy since 1997. But got exposed to the T brand and fell in love with their bikes starting around 2012, after trying many of them for decades prior and not meshing with their bikes (mainly MTB at those times).