Its not anti competitive in nature. Its a move to the other side of the competition/anti-competitive spectrum, by artificially creating a more competitive product.
Business by nature is anti-competitive. To gain marketshare you have to make your product more compelling to consumers, thereby reducing their attraction to your competitors products. MS methods do seem underhanded but since MS isn't the market leader in any major markets its probably isn't going to catch the wrath of any regulator.
MS is not making its product more compelling, they are making the competitor's product LESS compelling by their policies.