You are part of a professional community and the way you do your job and handle yourself professionally affects everyone in that community. Just as a rising tide affects all boats, taking a shit in the pool affects all swimmers. If you are dishonest with a client or employer, the designer behind you will pay the price. If you work for free, the designer behind you will be expected to do the same. If you do not hold your ground on doing bad work, the designer behind you will have to work twice as hard to make up for it.