Windows PCs are cheap because all of the garbage that comes pre-installed on them to reduce the overhead costs. So in the end Windows PCs cost about $50 more when $100+ worth of garbage trialware is bundled.
Still, everyone should be allowed to buy a computer without an OS pre-installed if they desire. Not everyone wants to pay more to build their own system just for the privilage. Plus, what if they wanted a notebook? There is no real choice there.
As for Apple... Apple has never been known to support consumer choice. They would love to lock people onto their hardware. Apple doesn't want people to know that their systems are merely PCs when OSX is removed... so they are unlikily to support such such a