Insufficient knowledge of the wear and tear on ones car.
Desire to "work for themselves" (despite the fact it really isn't).
TL;DR actors in an economic system are often not fully informed.
and whenever there's a knowledge gap, the "market" exploits it for arbitrage. But eventually (which may be a long time), this exploit would stop working as more people try to exploit it causing the profits from it to go down, or the lack of knowledge for which this exploits exist starts to disappear.
There's no rule to say that the market is super efficient at all times - just that it tends towards efficiency.
Seriously, though - we do. But regulations take time to catch up. As they should.