re: Wow. Just wow
Money perhaps? Some people do all sorts of things for money, which wiser heads would avoid.
Having your software on the App Store can net big money - the guys that wrote Ocarina (http://ocarina.smule.com/) had hoped to make $100,000 by the end of the year it released, but it netted about $400,000 in the first month alone - that app costs 99 cents. Just before that, the developer for Trism (a $4.99 puzzle game) got $250,000 revenue in two months (i.e. nearly 1,200 copies per day).
Developers will leave the platform because of Apple’s policy, no doubt about it – in fact last year there were more than a few articles about some quite respected developers doing just that very publicly. But the simple fact is, if money can be made, other people will develop for a platform/Apple doesn't care.
On the other side of the coin, this new Apple policy has removed some App Stores clutter. This developer - http://appshopper.com/search?searchdev=333206951 – alone had on the App Store almost 500 versions of the essentially the same photobook app… and I’m sure not all developers will be saddened by such news.