Why do photographers, actors, video artists, musicians, artists and film makers do what we do?
I can't speak for all of my colleagues but I can speak for many I know as well as myself.
We do it because we are retrospective. We do it because we love recording time, telling a story, documenting history.
We do it because it's the only thing we can think of that we like. We do it because as with any passion, without it, we are incomplete.
Often there's no travel and the pay is lousy but we continue to do it.
...but sometimes, just sometimes, we get to travel and we get paid well doing it, and free food, that's good too.