The Wilpons are opening a whole street of shopping and million square foot mall next door in 2016. They'll need good attendance to make as much money as possible.
The only thing that could throw this off schedule is if the business owners in Willets Point get the courts to delay their eviction. If this happens the Wilpons will be much less likely to supplement whatever they have through free agency. Building a contender would then rely on how many of their magic beans (prospects) sprout.
This trade just confirms they're going to go cheap and don't plan on winning before the date I'd predicted.
Do you really think there will be a all in place by 2016? Have the "squatters" or businesses all been relocated? How long will the environmental cleanup take? 2015 is wildly optimistic. 2016 is still unlikely for a mall to be built with tennants, etc.
Regardless, mall or no mall, if the team isn't winning attendence will not improve measurably. Historically, the Mets have drawn very well when they were competitive. Winning is the most cost effective way to put fans in the seats. Your premise isn't logical.