I think there are some people out there who can find something negative to say about any profession. Even in the case of some jobs, which have got a bad rap either generally or specifically, it's rare to find a person on the lower rungs who has any say in how that business is run. And the straight fact is that without these big, BAD industries (banking, oil, journalism, taxes etc.) society would collapse.
I have a friend who's fiance is in investment banking. He's only a fairly recent graduate, and he's still mostly at the filing/fetching coffee/data-inputting stage. But ask him, and he'll tell you all sorts of horrible things that people have said to him. His advice is just to let it roll off you. 9 times out of 10, the people who insult you don't know what they're talking about.