Would it be a bad thing for society if the antitrust laws were interpreted in this way? Why should these hardware vendors be allowed to exercise control over the software their customers run? Personally I think that open platforms are socially important, and I'm concerned that voting with my wallet isn't enough to protect and nurture them. Most people don't have the time, knowledge or interest to think about open vs closed platforms when they make purchasing decisions, and I think law is an appropriate solution to this market failure.

> So I could now sue Microsoft because I can only buy XBox games from their store?

Yes, though I have no idea if you would win. This decision doesn't decide that Apple has a monopoly or that Apple is abusing a monopoly. It decides that the end-user purchasers of apps on the app store are Apple's customers, not customers of the app developer only. It follows that they are entitled to raise a suit that Apple is abusing monopoly powers in a way that harms them. Whether Apple has a monopoly, and if so, whether Apple is abusing that monopoly both remain to be decided. (My guess is neither.)

It's all relative, but I don't think a game console can be compared to a general purpose pocket computer. Even Apple has been marketing the iPad as a laptop replacement.