I don't see why Apple would pull the plug. Sure, the app store has its problems (and I dislike those too) but it seems to me their only danger is that they are

I don't see why Apple would pull the plug. Sure, the app store has its problems (and I dislike those too) but it seems to me their only danger is that they are competing with Apple directly. There is already Kindle and iBooks... and there may very well soon be more. I don't think Apple really cares that much, who sells the books. Especially if, as in this case, they still get their 30% share.