Hey, it's just getting broken in. At one time the Prius taxi was common. Now they all seem to be out of service and sitting in a garage on Staten Island. For less than $2000 if the cars only last another year the buyers got their money's worth.
I believe Yellowcab in NYC has a maximum age for vehicles right? So a 2010, perhaps purchased in 2009 is now just over 5 years old. But then I think the big problem is that NYC now requires all hybrid vehicles to have a large interior room, disqualifying the Prius. The Prius V is OK, but not the Prius liftback. So all those Prii will disappear soon. If Bloomberg had his way, they would all be replaced by the ugly Nissan "taxi of tomorrow" crap. Not available in hybrid...
As an outsider, there seem to be three criteria a taxi must meet: Age, mileage, and it has to be on The List.