The idea that pushing diversity means promoting lesser qualified people over qualified ones.
Would it really bother you if all the firemen pulling your daughter out of a blaze were black men?
Or do you want less capable men and women to do it just to have 1 white guy, one black guy, one Chinese girl, one gay Muslims, one Indian in a wheelchair.
Another idea is which is less clear cut is when you question what "Diversity" means. For example a lot of people complain that Hollywood movie roles don't fall in line equally with population figures.
But that's stupid to me, because it's not taking into account what Hollywood movies are. So for example if they did another movie about the Normany Landing, should they insert gay lesbian Chinese women into the mix just because there are no lesbian Chinese women in Hollywood?
But if you mean just the general idea of "It's cool to have a mix of people." as a thought experiment, then no it's pretty hard to find a valid reason to hate on it aside from predjudice.
All this, except for one thing - Hollywood movies DO line up with American racial representation. Look at the graph showing the racial breakdown of movie characters, and compare it to American census data. ---
'It's okay that those gangbangers stole all my personal belongings and cash at gunpoint, cuz they're building a rec center!' - OneTimeBen