I expect their rational on the matter is that they can continue to sell hardware to people for the purposes of running OS X on cheap machines, but can avoid Apple's lawsuites due to the fact that they ship a different OS.
I would not be surpised if they just dump a default install of Ubuntu on it with no attempts at quality control, or making sure that all the hardware is supported, or anything like that. Without a review telling me otherwise I would not choose to purchase from these guys.