I agree with most of the points in the article but I am mostly troubled by something that I haven't seen mentioned, yet. That is, scaring off potential developers with such an arbitrary and heavy-handed system, more will take their collective brainpower to the other platforms, such as WinMo and Android.* This will leave the iPhone to eventually be like the Mac was in the early days: Too closed to be worth developing for. This, in turn, will lead to decreased market share and less developer support in the future. It will be a self-sustaining spiral which allows competitive platforms to catch up and pass the iPhone in terms of features and capabilities.
Ultimately, I don't really care if my next phone is an iPhone or something with more developer support. But, I really don't want my next phone to be another phone like my previous WinMo phones that lacked an elegant UI and solid features but had lots of developer support. Apple has made this mistake before and I fear they're trying to do it again. While many, including myself, felt the Mac OS was always more elegant and consistent in its user experience, the reality was there was more you could do with a Windows machine, warts and all, because it was more widely-supported by developers. Now, the differences between MacOS and Windows are slim enough that it may not matter which I choose to buy next. I suspect the same will be true in the phone marketplace.
*That point has been discussed.