Nobody knows (or at least I don't) what this has cost, but given that people around the world have been using railways and motor trucks for over a hundred years, I'm guessing it's in the tens of thousands of lives, billions of manhours, and trillions of dollars. Think about that for a minute and you'll see the importance of Dana Blankenhorn's blog entry yesterday, Microsoft's winning anti-Linux strategy warning that Microsoft could intentionally pull off something similar.
His idea, and I'm sure he's right, is that Microsoft is trying to establish PC security management as a profession in the expectation that the professionals produced will then help keep Microsoft in business by insisting on the products they know how to distrust.
If Microsoft pulls it off, they'll have set a new standard in the black art of succeeding through failure because, of course, those people wouldn't be needed if Microsoft built reasonable security into their systems -and that tells us something important about their plans for the future. Specifically that Microsoft will have to choose between abandoning these people, or expanding the market for its own security products and services simply by failing to make its next generation products any more secure than its current ones.
You'd think that would be an easy choice, but how many heavy trucks do you see rolling around on eighteen inch wheels? So you're right, they are likely to consider this an easy choice, but they won't make the choice you or I would.