This doesn't seem that unreasonable - weren't/aren't medallions over $1M in NYC, which is a factor more expensive than labor, fuel, or maintenance of a vehicle...
Yep, and they were all effectively owned by banks who leased them to cab drivers on a per-shift basis. Your cab driver has to pay ~$150 (I don't know the actual number) per day to drive a cab, so until he makes that $150 back he is losing money. If you had to do this every day, knowing there is a chance you might lose money by going to work, well, you'd be a pretty miserable human being -- just like most NYC taxi drivers.