One thing that I noticed when I had to switch from a Linux desktop to an MBP is how much worse text anti-aliasing is. The crispness just isn't there, especially at smaller font sizes.

Certainly the MBP has a high-res screen and can live without it, but it's highly reflective, and anti-glare external monitors provided by most employers are mere FHD, and most fonts become unpleasant and hard to read without anti-aliasing on them.

Maybe anti-aliasing was just hard to implement nicely in OSX graphics stack, they struggled with it, and decided to remove it.

I suspect that most of Apple's "proper computer" sales are laptops where they put a retina display anyway, and if you shell out $2k for a laptop, you can afford to spend $300 for a 4K external display.

In other words, they (correctly) decided that theirs is the premium segment, and that segment can afford to switch to retina-only hardware.