I can get Windows hardware for dirt cheap. Much cheaper than any Mac hardware. So if I am using the computer as essentially a dumb terminal to connect to a service over a network, there’s no reason to buy Mac hardware. Yes the hardware is janky and the OS is bad. But I’m getting what I pay for, and here my needs are modest, so why pay more?
Besides that, some people actually like Windows, or dislike Macs, though I’m not one of those people. I prefer the Mac. I just see when the Mac is a poor buy compared to Windows.
Those aren't the only two options. There's not really any such thing as "windows hardware" - and if you really want maximize performance of low-end hardware, Linux is really the king for that use-case.
A lot of low-end hardware will not even run Windows 11, which is probably going to be more and more of a pain to deal with as time goes on.
I have to run proprietary software on it. Installing it on Linux is a pain. It’s doable in Linux, but the hassle of Linux gets me absolutely nothing in return here. I’ve used Linux extensively so I know.
I don’t need to maximize the performance of the hardware. I don’t need Windows 11.