I suppose that is why the casual technology market is booming so fast. One word, Portability. You can't find that in a heavy laptop or desktops. Peopel want to be flexible and find enjoyment in many things.
Most people like to do a variety of interactive things. Consoles allow this. Aside from fps games, Nintendo has always been notorious on this aspect. Microsoft and Sony took the hint and now they are as well. A console last roughly longer than that and only costs small extensions in between. Its also more portable and runs on a TV, which can be used for other entertainment purposes.
On the other hand a serious gaming on a pc requires a good video card and numerous upgrades every 2 years at the least. The majority of its setup only revolves around a keyboard and mouse. Not everyone wants to keep up their hardware or care for a ~8 lb laptop.
Finally, Angry Birds is hardly a graphic intensive game. B.c the ipad supports it and can manage to run NFS doesn't make it even comparable to a gaming system, let alone pc/laptop. This guy doesn't know what he's talking about. On that note I'd like to say I do enjoy Angry birds, and also like console and computer games.