By comparison, you're not supposed to change your iPad's battery by yourself.
Suffice to say, not all manufacturers are the same and not all products are the same. And frankly, so long as the tinkerers are being serviced, I don't see society as having lost anything yet, just because a single more appliance-y product has hit the market.
And --specifically to the matter at hand-- particularly not when the appliance-y product in question has a first-class, standards-compliant web browser.
I say that I am disappointed in it because of the App Store and suddenly I'm the one being called a luddite, being accused of wanting to keep the poor masses down, and other silly things.
I think any technology enthusiast will tell you that they would love nothing more than to never have to do tech support for peoples computers. I assure you, that part of the iPad is universally loved.
The disappointment some of us feel is because we were hoping for a tool for us to use as well, and it's not really what we were hoping for.
Specifically, those friends and family who constantly call you for tech support are friendly enough when they see you, but they deeply resent having to deal with you every time their computer breaks down. It's not personal. They just hate that it's "their fault," or that they have to lie because they really were surfing sketchy porn sites. The iPad solves that need.
I think that's just it: it seems (and for most people, actually is) far harder to learn to work a computer in a powerful way than it is to learn to read and write. The number of facts you have to know to properly administer a modern OS is staggering. One could reasonably argue that the iPad has gone too far in the "easy" direction, but it seems difficult to argue against the idea that computers thus far have been "too hard". If we can provide the ability for people to achieve powerful results with their computers without having to learn the intricacies of their OS/hardware, we're doing good and unleashing precious talent. Every minute spent (by anybody who's not a sysadmin) dealing with file system errors and driver conflicts is a minute not doing productive or creative work.