I don't think that's true. We're regular folks too, you know. We want to, like, just do stuff sometimes. Hands up who owns a phone? What, you don't exclusively use your GPL Ruby VOIP client you wrote yourself one afternoon? Shame on you! :-P
Abstracting away the hierarchical file system is a positive for my mom, who can never find stuff she's saved, but I have no issues using one in the first place, so my gains are smaller. She'll be thrilled not to have to navigate an application installer or download some component from the web to run something, but doing that is nearly effortless for me.
It's no loss at all to my Mom that the iPad can't run some GPL Ruby VOIP app she wrote herself, because she can't write a Ruby VOIP app. By contrast, I would be giving up my ability to write and run my own Ruby VOIP app.
Overall, I (as a very tech literate person) benefit less from the positives and feel the pinch of the negatives more than my mom (or any less tech literate person). It could still be a good trade for me, but I wind up looking at a totally different values proposition than my mother would.
 - I have no interest in writing a VOIP app.
This is utter nonsense. That's the same as claiming, that the more tech literate you are, the more ugly UI you need. Ease-of-use means being more efficient for everyone. Or are most tech
literate still punching cards?
iPad is not the device you will do your tech literate stuff: you will use your computer for that.
Why do people think that iPad has to replace something? Sure, if all one does is browsing, some emails, and a couple of games, iPad may be the he or she they needs. For others (including "tech literate" people), it makes a great complementary device, best suited for browsing, e-books, etc. I wouldn't want to hack in Ruby on iPad, but when browsing on my couch with my iPad, with its IPS screen, portrait orientation and amazing multitouch UI I couldn't care less about all the freedom it has not.