I would love it if cases like PCalc never even happened. But I'm willing to accept that sometimes bad decisions happen, and we have to do our best to see that it gets fixed.
Edit: To clarify on Drafts, I definitely think that they need to be consistent with their policies, though that can be very hard when you have lots of different reviewers reviewing apps, as they may interpret policies differently, or simply be more or less diligent about enforcing them. But Apple has always said that the notification center is intended for information display, and it follows that having a bunch of apps use widgets that provide buttons to launch the app is in violation of the intention of the notification center. Apple should be consistent here, but I would not fault them for choosing to tell all apps (such as Evernote) that they need to remove similar buttons, rather than allowing Drafts to keep its button.