That area behind the docks is (now was) perfectly fine for shallow draft boats including my tritoon.
I live behind those docks for a good part of the season as it is near impossible to get a front spot on a busy day, and even if there is a front spot I try to leave those for those who can only park out front.
If they actually did some research PRIOR to making decisions, photos of the docks on weekends would show that there are (now were) always 'toons and jetskis parked back there in the above 'yellow zone".
Prior to adding additional users to the existing docks, make sure you can support the current users...