Correct me if I'm wrong but I imagine that's more for the tooling (e.g. syntax highlighting for my template and styles) than an actual preference for SFCs.
Shrug. Maybe? I think Vue is popular enough that if people actually disliked SFCs once they started using Vue they you would see blog posts about how to avoid them, complaining that's why they're leaving Vue, or tooling that makes it easier to bypass them. I don't really see this so my assumption is devs generally like them once they start using them. I could certainly be proved wrong.