There is just a lot of assumptions and unproven statements in your post. I've heard that so many times, it sickens me.
Some anecdote: A few months back, when Adobe announced Flash support on the iPhone, basically everyone in my circle of friends was like "woohoo, soon i'll be able to play those flashgames!". Now, everyone is just repeating the marketing talks, that flash is bad and whatnot. Basically i have the feeling that many people don't reflect what Steve is saying, they are just repeating the marketing talks. Basically, that's what is driving me mad.
Also, i don't see a reason why a desktop OS wouldn't work on a tablet (except for the aforementioned appstore lock in). Display too small? Nope, works on small netbooks, too. Can't hit the buttons? No, i am currently sitting in front of Windows 7 and i can't spot a button that i couldn't hit with a finger. Links in Websites are usually way smaller then the buttons in the OS and you still can hit them on the iPad, don't you?
Also, a few months back it was "oh no. Multitasking? That's sooo draining the battery, we won't allow that!". Now, that android poses a threat it's like "uhh, we miraculously implemented multitasking!". The real move behind holding back multitasking? Get people to use apples notifications, another factor that ties developers to apple and sends user data through their system. Another move to more lock in.