A few things here. First, as a consumer I might hold them to that expectation, but that is not the same as the law holding them to it. Second, it's a bit backwards to use Microsoft as an example of not sunsetting old versions or having newer versions that are slower or don't work [as well] on older machines. Third, this is about locked down software environments by hardware manufacturers, a completely different situation from software manufacturers providing the freedom to run on lots of hardware.