Are there more white people at WDW then any other color? Probably. Is it an issue? Depends on the person. Not denying the fact that people have felt prejudiced against because of their specific race. But as for the lack of diversity - no one is forcing anyone to be at WDW (unless you're an employee, and even that is a choice), so without getting into the socio-economic argument about who can actually afford to spend money on a park ticket and resort stay, the breakdown of people walking around at WDW is a direct result of the people who are purchasing tickets and walking through the gates.
Have people been treated differently at WDW because of who they are? Probably, and that's not right. Doesn't mean it won't happen again, and I don't know the answer on how to stop it, other than people becoming more accepting of others and being more open-minded. But being treated differently or causing a reaction from people around you is not limited to race, it could be from size, smell, clothing style, a disability, speech pattern, volume level, hair color, etc. Just be comfortable in your own skin and enjoy yourself at Disney! If that's a problem, then either choose to be uncomfortable out in the world in the majority of situations where you can't control the reactions from people around you, or limit your life to environments made up of people that are just like you.
Oh boy. Just read through the other posts. Judging from the thread title, I thought it was about diversity, but perhaps it was about something else. Ugh.