[tgsovlerkhgsel]

It boils down to the lack of a reputation system. There is little incentive for drivers to behave in a good way, because anything bad he does won't directly impact him, beyond maybe make people avoid taxis altogether (which seems unlikely, as taxis are usually a last resort when you have no other realistic options). And it doesn't take many bad apples to spoil the bunch.

One of Uber's main contributions is changing this dynamic.