With OS-X there are now many Mac users that are far more technically adept than the avarge PC enthusiast.
And
most PC enthusiasts are far more technically adept then the average Mac enthusiast. Spent about a decade on Macs here and up until about a year or so ago was a still a regular particpant at Mac forums, I'll gladly have this debate

I don't understand your using OSX as an example of anything, varrious *nix builds have been available for PPC for a long time including numerous builds of Linux, OSX just adds tons of bloat. Sure it's better then OS9 or anything earlier from Apple, but what isn't?
As I stated in my last post, there are some very knowedgeable Mac enthusiasts- but they pretty much all post at Ars already. The Mac faithful that would be drawn to this site would be butchered by this crowd. They tend to be equal parts arrogant and ignorant, not capable of debating the finer points and relying time and time again on the 'look and feel' BS that they have been spoon fed straight out of Jobs' RDF. That line of argument will get them laughed at here, and none to kindly.
Simply look to people here that are PC enthusiasts looking to buy a prebuilt and are openly laughed at or called fools, and this is when they have the choice of buying whatever the hell they want. What do you think this same crowd would say to the people who only could buy what Jobs so deemed them worthy of having? They will resort to the normal 'Wintel' banter that they cling to, in an AMD dominated forum. They will talk about Gates' evil deeds, and have his billions in charity thrown up against Steve Jobs letting his own daughter live far below the poverty line while he sat on hundreds of millions of dollars. They will tout the virtue of single button mice while the PC enthusiasts will be in tears at the thought of giving up their MX500/700s and their 7/8 button mice. They will talk about ease of use and the crowd here will fail to comprehend what they are talking about. They will lament the lack of stability of PCs and yet again they will be met with significant confusion from all the users who go months regularly without a reboot. They will boast of how any application you can get for the PC they can for the Mac, and they will be hammered with PCs have it all, more choices, and can play all the games. They will try and sing the virtues of the PPC architecture and this crowd will pour dump trucks of benchmarks on to them showing the reverse. They will try and talk about the superiority of SMP while the sizeable crowd of SMP PC users here will quickly point out their advantages in price and performance. They will try and argue the superior visuals of the Mac OS while the PC users here will simply show them what is possible with WinBlinds and the like.
Against normal prebuilt buying straight 'Dell' PC users Mac enthusiasts are at an enormous disadvantage in discussions, here they are a sacrificial lamb waiting for the slaughter.
And AT isn't exactly full of computer savvy people, unless "computers == games", which seems to be the most common attitude around here these days.
AT may not be loaded with tech savvy people, but even the average AT poster is far, far more tech savvy then the average Mac enthusiast, and there are enough people who are tech savvy to back up the AT regulars. If a Mac forum were created here it would quickly devolve into a Battlezone in which the Mac faithful would stand no chance if for no other reason then numbers alone, let alone that they are dealing with a prebuilt out of a small handful compared to ~100K purpose built rigs. There are a few good Mac forums around, and there is always Ars for cross platform discussions, here the crowd that would be attracted would end up being violated in every way possible over a discussion forum and turned off to AT in general due to the forums.