[least]

> But that’s also weird, because I would figure that people who care about the brand tend to not build their own computers (is this assumption wrong?), instead usually opting for the fruit brand.

Mini-ITX computers are a niche among a niche market of PC builders. Form factor is inherently a consideration being made when you build one, given the added difficulty and compromises one must make to build one. In that sense, it's pretty obvious that people building such computers would care about the aesthetics of the case they're building in. This also isn't terribly expensive in the world of boutique mini itx cases, where one can easily spend double that on some of the more exclusive ones.