If Pystar want to risk it...
...then why not let them run Leopard on "illegal" kit. It will be Pystar who get the support calls, have to write the new drivers, do all the testing etc. etc. If I buy a Mercedes engine, can Mercedes block me from fitting to a Lada? Nope. It's still won't be a Mercedes, just a quick Lada (and in need to new suspension, chassis stiffening etc.)
As for an Apple monopoly...I can't see it. I can spunk just as much dosh on any other PC as I could on an Apple unit (Alienware springs to mind). True, price does not always make somehing "premium", just expensive and another brand doesn't have the fashionista caché of Apple, but who cares what the fashionistas think? Bunch of wankers.
So no, I don't buy the whole "Apple monopoly" bit. Unless Apple grabbed 75%+ of the market while I was asleep...? Nup? Thought not.
Apple are just making themselves look like monumental dicks, but it's their ball and if they want to play at petulant; that is their choice. It's a shame Pystar didn't take their money/energies and jump in behind a premium Linux distro, helping to making Linux usable by Joe Schmoe for the first time ever. But then, Linux tends to bring non-techies out in a rash.
So we're Apple just acting like a bunch of dicks. And short-sighted dicks too. They could easily license to Pystar, with strict controls over quality/how/where it's branded and at what price-point. That could leave Apple in the "more-money-than-sense" market, and Pystar grabbing at the lower-end of the market. This could help increase Apple share overall and surely that's a "Good Thing"(tm) isn't it?
Or are Apple simply worried about losing kit sales to Pystar et al?
Either way, Apple want to restrict the sales of their OS, they are not running a monopoly in any meaningful sense and it is thus their choice.
Oh -and to the idiots in the balcony: no one is asking Apple to release code, just license/allow install on non-Apple platforms. Source Code!=Run time.