That's odd, and definitely not normal.
Firstly, the Prius was the least expensive model maintenance-wise in the link above.
Secondly, I have heard from multiple people that the Prius engine just keeps running because it doesn't get the same loads as a normal car (makes sense).
Finally, taxi drivers drive reliable vehicles that are cheap to maintain, and the Prius is the car of choice for taxi drivers where I am (and here that's categorically not a side-effect of other financial incentives).
