Horace Dediu, in an interview on Microsoft Surface:
In contrast Apple sees the iPad as a new type of device that is used for things not directly related to PC style computing. In that sense the iPad competes with PC non-consumption. It means people may own both a PC and an iPad and some will own only an iPad. The iPad will expand the market while taking share from the PC. Windows tablets will try to hold the Windows share steady.
I think it’s a hard concept for people who are comfortable with technology to understand how much different the iPad is. If you’ve never seen someone who’s never been able to make use a computer grab an iPad and start making art, reading news and keeping up with friends for the first time, it’s sort of amazing. I don’t think my mom could ever make heads or tails of PCs, but I bought her an iPad 2 the day it came out, and she’s used it every day since. If you haven’t seen or experienced that, the idea of an iPad being anything different than a PC, or that there was ever anything wrong with PCs (I mean that in the “personal computer” way), just isn’t going to compute.
The place it becomes most obvious to me is whenever something stops working on my Mac in such a way that I need to edit a configuration file, or do something using Terminal. I think, “What does someone who’s not extremely good with computers do under these circumstances?” Accept it as broken? Try to get someone to fix it for them (Mac users at least have the Genius Bar)? Assume it’s their fault? With an iPad that just isn’t a concern most of the time. I’m not saying its perfect – we’ve got a long way to go – but no one who uses an iPad should ever need to worry about it “breaking” in the same myriad ways that PCs do all the time.
Microsoft doesn’t see it that way, or they’re scared to.