The reason I'm not a big fan of rules about limiting reshuffle luck is that I feel that the strategy in managing reshuffles is more than worth it.
In a lot of games, "strategy" usually includes setting up safety margins so that luck doesn't horribly destroy you. Dominion is no different. Really, a lot of Dominion strategy is about adding in redundancies and accounting for as many factors of luck as possible.
Consider the situation you describe about a Witch that misses the reshuffle. Yes, in this instance, it sucks. But what about a game where you have an engine, you've played most of your action cards, and you're just before a reshuffle. Do you keep going, or no? In the Dominion we play now, this is an interesting choice because you have to balance a better reward now + worse hands later with decent reward now + consistent hands later. And it's not at all clear which is better, and that rewards skill with the game. However, if you know that you can simply reshuffle, you can just keep going, and shuffle all your engine pieces in. This removes the risk in "risk and reward."
Still, in a tournament setting there do need to be some limits on luck. Identical hands is useful on some boards (but arguably detracts strategy space on others). But overall, the tendency for reshuffle-skipping is to create interesting decisions, and trying to stop reshuffle luck removes some of those decisions that help separate skill levels.