A great many people really like OSX; its been a long time since i've daily driven it but there's stuff about the way it works that feels more efficient than windows, and easier than linux. That's not something that appeals to everyone but its obviously worked for a lot of folks.

So back in the day it was about getting to use OSX (and in other cases apps that were OSX only, or just ran better in OSX) but not having to pay so much for the hardware. That's a calculation that to me really only made sense for desktops; as for quite a long time Apple's laptops weren't actually massively more expensive than a similarly spec'd windows laptop.*

Overtime i'd argue that linux desktops have caught up to a lot of what made OSX feel good; but they're not like for like even now. Though take that with a grain of salt as I spend more time in cli/tui nowadays across my macbook, work windows laptop and various linux boxes i've got running :)

*The thing was that the average windows laptop was under-spec compared to a Macbook Pro so the latter always looked way more pricey.