To be fair, if a company wants to produce something that only works on one set of hardware, that should be fine. We simple choose not to use it, right? And many of us /do/ choose to use it? But why do we choose to? Because we find that we're too busy to maintain a Linux-based workstation.
While there are questionable practices by Apple and many other machine producers, what you can't argue against is that in limiting the hardware that MacOS has to work with, they're able to deliver a level of stability and user experience that you don't get with Linux.
Sure, it would be great if we could replace the batteries, if we could upgrade the memory, and easily fix broken parts, but that isn't the company's ethos. The company produces devices that are plug and play, high grade consumer electronics. Nobody forces us to buy these products.
Anyway, that being said, the framework machines look super interesting and if they were UK available, I'd probably get one for a non-critical Linux-based workstation.