Apple reminds me of homeland security, but prettier!
Because, in fact, the sale of gas is subject to a great deal of regulation. That's to prevent someone from selling you adulterated gas that destroys your car's emission system. Or from selling you leaded gas that pollutes the air that our kids have to breathe.
And the reason the manufacturer doesn't need to enforce your use of the roads is that it's already being enforced by a higher authority. We have cops for that. And they very much do dictate that you keep your car on public roads, and not go driving off across someone else's lawn, or the National Mall.
If you think these extensions to the metaphor make no sense, you're missing the elephant in the room: Personal computers are insecure, and the average web surfer is more likely (probably, alas, by an order of magnitude) to have their computer steal their credit card numbers or grind to a halt under a flood of malware than they are to crack open the box or write a single line of code. An enormous number of people don't want the freedom I want, any more than they want to own an acetylene torch.
To your other point, Windows is insecure, not personal computers. A true personal computer is/would be owned by me, not a corporation, not a hacker.
Hmmm... Seems to me I've seen this freedom vs. security argument elsewhere...
I suppose the argument then is that you choose to limit yourself to what the iPad offers by buying and using one. As long as a priori most people understand what they are getting themselves into when they buy an iPad, I think everyone would agree that people should be able to make that choice. The problem is that a lot of people aren't going to understand beforehand the limitations of this device, so they won't have made a fully informed choice.
You seem to be assuming several things: that this is peculiar to the iPad, that people who do understand the limitations also care, and that if they don't make fully informed choices about things they care about that it is someone's fault other than their own.
I don't think those are accurate assumptions.