Likewise, I love FISMA, but I don't think hospitals would cease operations just because their systems couldn't get an ATO. What kind of accountability would motivate them to complete POAMs with any urgency? I don't think there is an effective way to incentivize a proactive approach - financial penalties would simply be indirectly paid for by customers.
I this case I think they could just have the proper regulations and use the "stick" portion of "carrot and stick" with fines.