I would say Apple is more artist friendly than business friendly, and that's a perfect place for these high end Razor Blade machines to give them a run for.
They run (an old version of) the FreeBSD userland, but I would hesitate to say that the "work well with Linux".
It's tolerable, but it's hardly a stellar experience. Things like suspend/hibernate, fan control, etc. are problematic, even though they're fine on most other pieces of hardware on the market.
I always sigh a bit when I hear people recommending installing Linux on a Macbook, because they're not getting the full experience - they end up thinking that Linux is buggy and doesn't support these functionalities well, when the truth is that it does, as long as you use hardware that is actually supported.
There are a number of reasons that Apple hardware will probably always be a sub-optimal platform for Linux. There was a HN comment a while back from one of the Linux kernel developers responsible for maintaining the MPB drivers who explained why this is the case, though I can't find it.
I don't think he means by "works well with Linux" that macs actually run Linux even ok. Which is clearly not the case, a mac running linux is waaay shittier than say a Lenovo W540 running Linux.
Running Linux on a Mac is not a good idea. Just getting it to boot is a 4hr plus long endeavor. Best to run Linux in a VM on your mac. Windows on Mac is a better idea than Linux.
I think by "works well with Linux" in that it has a bash shell, has Homebrew, etc.