Even if they've painted a bike lane on the pavement, if the majority of park users are peds, it becomes a defacto ped park. The people have had their say on how they want to use that particular bit of parkland. Everyone deserves their day in the sun.

Instead of getting irritated, acknowledge that you've outgrown that park and are ready for bigger things. Ask around - there are so many awesome rides in the NYC area that don't involve constant red lights or parks full of strollers. Any bike store employee, and any courier who isn't a jerk will be happy to kick down their favorite Sunday rides.