Dismissing smartphones as a fashion trend seems naive. There is a segment of PC users who emotionally react to the suggestion that the "PC", in reference to a box sitting on a desk, is in its twilight. I think it's due to a fear of losing mastery over the system.
PCs are horrendously complex for what most people would use them for--taking pictures, browsing Facebook, watching movies, and so on. It's no surprise that, as mobile devices have made these things easy to do, PC sales have been on the decline.
