There's a difference - software also has unplanned obsolescence. For instance, I've been working on a non-profit website that has a fair amount of QuickTime video from way back when that was a good choice. If you don't do something about it, it won't play anymore on modern browsers. It's hard to align the interests of software developers with the interests of customers using a one-time purchase, but with work that continues indefinitely. Appliances are different since I don't need their features to change long after the sale. In this case, if they can charge me more at the time of the sale for an appliance that lasts longer, we can align interests.