It is a political time bomb no matter who is in charge regardless if the damage was done by an Act of God (Hurricane Sandy).
The L Train's shutdown was going to occur for 15 months. That's a long time. I don't doubt that it was necessary, but i'd be livid if i lost my main commute for 15 months.
On the flip side, if its going to take 15 months with a full shutdown, it's going to take forever with a partial/slow service.
What do people think about a slow of service, then going into a full stop of service with significant communication? People would be nudged to find alternates and spill over isn't going to overwhelm alternate routes.