Well, based on that, then portraying an Islamic terrorist shouldn't be a problem.
Okay, I have to point this out -- they're not "Islamic terrorists." They're Islamists
-- members of a political
movement that uses a radicalized interpretation of religion as a rationale. Terrorism cannot validly be described as "Islamic," because committing terrorist acts is a violation of Islamic law against the killing of women, children, and non-combatants. These are not people practicing a religion, these are people pursuing the political goal of creating a theocratic state, and interpreting Islamic law very
selectively (and often quite dishonestly) as it suits their political agenda.
And again, it's a matter of context. The problem is not that there's an occasional depiction of Arabs, Muslims, or other Middle Easterners as terrorists. The problem is that it's a pervasive media stereotype -- and, worse, one that leads to a lot of real-life discrimination. Storytellers have a responsibility to enlighten and inspire, not to promote intolerance.
Re your earlier thoughts that it'd be okay if a balanced view is shown, i.e. also showing good members of whatever ethnic/religious/national group is cast as a bad guy - is it really a good idea to place such a restriction or rule on entertainment?
It's one thing if you choose to write a story including a carefully balanced group of characters that softens offensive ones. But do you want to HAVE to?
I call straw man. There is no such restriction or requirement, however much it may seem that way to you. Like I said, it's a matter of responsibility. There's more at stake here than stories. Real people, good people, loyal Americans who practice Islam or are of Middle Eastern or South Asian descent, are being persecuted by ignorant or racist people. Any responsible American given the opportunity should speak out against that injustice, should do what one can to enlighten the ignorant and give succor to their victims -- not as a matter of some imaginary fiat, but as a responsible personal choice. Not because it's "politically correct," but because it's morally right. And the tellers of stories have a powerful forum for fighting ignorance, intolerance, and injustice. It's only right to use that forum to fight lazy stereotypes rather than perpetuating them. I applaud the writers of this story for doing that, because, contrary to what you're claiming, it's something that isn't done nearly often enough in my experience.