I really think that people should not take a job if they feel morally uncomfortable with any aspect of it. If you don't want to drive people to a certain place, don't be a bus driver. If you don't want to provide certain treatments, don't be a doctor. If you don't want to sell a certain product, don't work in retail (or at least, not in a shop that sells it). I used to work in a shop that included a pharmacy counter. We were a small branch so there was only ever one pharmacist on duty at a time, and only a pharmacist can dispense medication. He was a strict muslim and wouldn't give out the morning after pill. So when terrified teenage girls came into our shop he would explain to them, out on the shop floor, that he had a moral problem with their choice and couldn't give them what they'd come for. Then they could walk to the other end of town to the bigger branch - unless they came after 6, when that branch was shut. Used to make me fucking rage.