Well it mostly maximizes financial returns (for the drivers and the company) by enabling up to 5x higher prices at 'surge' times.

How would you feel if your taxi driver told you: "oh sorry Sir - you want to drive home? Today that'll be 5 times as much as usual. We are kinda busy, ya know". Unthinkable for taxis. Accepting for the 'disruptor'. All but very rich people would rather wait a few minutes longer to get a taxi than to pay up to 5x as much as usual.