I see inequality based on sex, skin color, and other lines in my society, yet I’ve met almost no one who overtly supports sexism, racism, or other lines. And among sexist, racist, or otherwise divisive people, most seem motivated out of ignorance, which seems easily remedied.
Usually I say that systems perpetuate inequality so people who participate in those systems inadvertently support them.
I recently noticed an odd effect that may contribute more than anything else and perpetuate minority groups remaining disadvantaged longer than other effects.

The problem

When groups are disadvantaged based on something easily recognizable like sex or skin color, people within that group tend to organize. Groups form, leaders emerge.
Now consider this: can those leaders emerge from outside that group?
Can you imagine a white leader emerging to represent non-whites working for racial equality, a man leading for women’s rights, a Christian leading Muslims seeking fairer treatment, or the like?
I don’t mean can men represent women at all or can whites lead blacks at all. Of course U.S. Presidents have all been men and most of them white. I mean can a man lead women specifically to get equal rights for women; or the equivalent for other groups?
In areas where I’m in the minority, like religion, for example, I can’t imagine a person with opposing beliefs representing me. I wouldn’t find them credible or knowledgeable about my deepest issues, able to sustain support for long, or able to be taken seriously outside the group. I can’t imagine members of other disadvantaged or minority groups feeling different for their situations.
Can you imagine a white person giving an “I have a dream” speech? Can you imagine blacks traveling such great distances in such great numbers to attend? What would you think of the response among other blacks or whites if it happened?
By Wikipedia’s description, many men would qualify as feminist, but few men take it up and I don’t think many women call for men to lead feminist organizations.

Feminism is a collection of movements aimed at defining, establishing, and defending equal political, economic, and social rights for women. In addition, feminism seeks to establish equal opportunities for women in education and employment. A feminist is a “person whose beliefs and behavior are based on feminism.”

The result

If people in minority and disadvantaged groups don’t accept leadership from outside them, they will always be led by people within them.
The result is to perpetuate otherness. If a group grows to no longer be a minority or gains advantage to no longer be disadvantaged, the pattern could change.
Otherwise there remains an odd catch-22. If leaders from a small disadvantaged group only come from within it, it will remain outside the mainstream. To the extent members come from outside it, they will not likely rise to leadership.