I have no idea why it was canned, but it was a very expensive server with a very expensive SAN solution. I think it just didn't compete well with other enterprise class machines on price.

People are willing to pay more for a Mac Laptop/ desktop because the overall experience is nice. The screen, the construction, keyboard (save the shitty one), trackpad, Retina display, high speed SSD, etc all significantly affect user experience.

When the primary use case is sitting in a closet and serving up bits quickly, it quickly boils down to bang for the buck where the Mac has always lagged. The M1 could very well change this though. Particularly since power use is significantly better.

Also, when the Xserve was around, there weren't nearly as many iPhone developers looking for CI solutions. Seems like now there would be a pretty healthy demand for that alone.