Indeed. Computers didn't become popular because Joe Sixpack wanted to watch porn and update Facebook. They became popular because Joe Sixpackatwork could click shit in Outlook and Excel.

(And 8-core desktop-class machines with 64-bit address spaces were obviously popularized by the need to run Eclipse, but I digress...)

Agreed, but this is kind of an "80-20 rule" thing. 80% of the time is spent on those 20% of activities, and 80% of people are basically just doing email, browsing, Twitter/Facebook, and media/entertainment. Even people who do more complex things with computers spend part of the day just doing those things as well, which is why there is an opportunity for a dedicated product focused on these 20% activities (and why Apple and others think the potential market for iPad-like devices is so enormous, despite the product type being extremely limited by design).

Also, even Apple does not think everything falls into their 'walled garden', so they'll continue to develop and sell normal computers for the other 80% of activities. But these new kinds of products reflect the shift in the set of activities that dominate modern computer use. The shift allows them to create a viable product that mostly ignores 80% of computer activities, and moreover, by omitting those other things, different design decisions can be made (e.g. walled garden app store) to make it much easier for them to meet the new set of requirements demanded by these media consumption type activities (e.g. battery life, appliance-level reliability). Those design decisions don't work with normal computers, as the requirements are different (e.g. completely general purpose use very important, battery life less important or unimportant [desktops]). So I think it is a mistake to think that even everything from Apple will be walled.