[jkot]

Four engine aircrafts are also more difficult/expensive to maintain. Most pilots prefer two engines.

[Symbiote]

I'm curious, why would a pilot working for a commercial airline care about the maintenance cost or difficulty?

[jkot]

Two engines have more spare power than four engines. Single engine on twin must still be able to fly aircraft.

[sp332]

Because they have to sit and wait every time there's an unexpected delay on the tarmac.