When you play a character, you get to see the world through their eyes. Whether it's a fictional world or a real world, you do get to see somebody else's point of view, whether he's a good guy or a bad guy.
We are all quick to point out all the differences but not as willing to accept what bonds us as humans.
Sometimes stereotyping happens not because of any nefarious reasons but rather because people don't know who you are or where you come from, so they go for the broad strokes about you, your culture, your faith, all that.
The box office has become global. I think that factors in to the question of how to portray different ethnicities and cultures.
When I read a script, if I feel it's written with the idea of just bashing other people, then I shy away from it. Sometimes it's some guy coming out with his own hatred, and I don't need to be a part of it.