I wouldnt under estimate the economic gains here. With $95M MEX on the line I am sure some pretty creative plans to skim the project are already in the works. I doubt the finished project will look anything near architectural drawing nor have its desired effect.
If they really want to re-vitalize the downtown, allow an inexpensive bus service between the cruise ship port and downtown, which would require challenging the taxi mafia. Face it, even Pod people are human beings and are aware of it when they are being ripped off by the taxis, this is their first impression of Cozumel, small wonder many do not venture past the port area.
Even better, instead of expanding Puerta Maya into the national park, tear out the existing pier (and the International pier) using the rubble to create an artificial reef north or Paradise and expand the downtown Pier to handle up to 7 ships.