Whose morals? There is no universal moral truth although Western countries may agree on a core set to the point its universal, but morals changes over time pretty significantly so when OP says “morals” what they really mean is “how I think the world should be”.

Because it gives you permission to see (a large percentage of) your fellow human beings as evil, and yourself as superior. I think it's worth reflecting on why it doesn't bother you. There is nothing evil about someone who works in advertising so they can support their family.

This is an absurd defeatist argument. Having morals and standards does not mean you want to feel superior. This is a surefire way to make sure we all lose moral compass, guiding principles and refuse to excel.