Hollywood maybe liberal in most aspect but lets face it, it is very conservative when it comes to Black men and white women either on screen or off. Remember Amanda Bynes she was basically the next it girl a few years ago then she lets the fact that she like black guys out her career hit the skids. Brittany Daniel can only seem to get work in Wayans brothers movies.
In hollywood you can be an alcoholic, drug addicted, party girl and get chance after chance, but date a black man and it will kill your career. The audience that these girl cater to want to think of that they can have these woman and the idea that they would prefer a black guy over them it too much for any of them to handle.
In movies IR is still rare but on TV I see it often.Amanda Bynes is a former child star and they usually dont make it as big stars as adults.Hillary Duff married a white man and her career has been dead for awhile now.Miley Cyras has a white boyfriend and her acting career is mostly over