I don't like Apple devices myself but I understand that some people like the ecosystem as a whole.
However I don't understand the point of a Mac without MacOS. The hardware is pretty much garbage compared to any laptop of the same price range, let alone high-end laptops like Thinkpads.
(this is a honest question and I am not trying to troll or make fun of anyone, in case anyone doubt of the tone of my post)
To answer your question, I don't see much reason to buy a MBP and run it without MacOS, because -- although the build quality is sensational and the MBP travels well -- I'd rather just buy a Lenovo with Windows 10 Pro from the factory, get their top-tier service and repair plan, and still come out cheaper than a new MBP. However, I could see myself converting an old MBP for use as a Windows machine.
For the same use cases Linux feels (and is) way more performant and responsive even on a less powerful hardware, and I'm not even talking about Docker.
The MBP keyboard is probably the worse on the market and any lower-end laptop keyboard is more comfortable to use. And nowadays it is not even a complete keyboard since it lack many standard physical keys.
The number of ports is extremely limited and you cannot connect anything without an adapter.
The computer gets hot very easily, and when it does, the keyboard gets extremely hot as well. It is also very noisy compared to any other laptop.
The glossy screen may look cool in a shop but it is very unpractical and uncomfortable.
I do not have any of those problems with my X1, I even have the best keyboard I could hope for a laptop, along with actual features like the Trackpoint, physical camera shutter or the PrivacyGuard.
Also, many people like to work with dual boot devices. And no, virtualization is not the same.
The hardware is also not garbage. It may not be competitive, but it is well made.
1.5) I like the GPL, apple doesn't
2. I like apple's hardware in a vacuum. As much as the company leaves a bad taste in my mouth (there is a deeply pretentious streak to Apple's approach to their users), they make nice cases and such.
Obviously if you just make websites it doesn't matter but if I'm buying an ARM device I want to play with the bare metal (you can't even access performance counters in MacOS IIRC)