Jason Snell of Macworld on Mac App Store restrictions:
Not only does this approach risk turning the Mac App Store into a wasteland of arcade games and one-trick-pony apps, it risks dumbing down the Mac app ecosystem as a whole. While developers can always opt out of the Mac App Store, they’re reluctant to do so. Not only are they afraid that Apple will one day make new Macs unable to run apps that don’t come from the App Store, but they realize that if their competitors are in the Mac App Store, they risk losing sales.
I see both sides of the argument. My friend Dave vowed at one point to quit the Mac the day that only Mac App Store apps were allowed. I think 3rd party backup apps are a necessity and I wonder if that will somehow, someday be allowed. But when it’s all said and done I am not sure that the impact will be as significant as Snell leads on. There are very few apps not in the Mac App Store right now and I expect that number will only shrink further in the next year.