As I mentioned above, while there are certain commonalities to being members of an outgroup, every outgroup also has peculiarities in its treatment. Women are not more likely to be imprisoned, black/gay/trans people are. Gay/trans people has religious opprobrium thrown their way, while black/latino people are followed around by store detectives and subjected to stop-and-frisk. White people can experience discrimination, but they do not experience racism; black people experience discrimination, but most do not experience homophobia. This means there is a limit to what white women, homosexuals, trans, etc. have to say on the issue.
Perhaps it has more to do with "if it ain't happening to me" than sorry excuse. I think black people are very homophobic. Most of the polls I've seen blacks at a high percentage think homosexuality is a sin or wrong or disgusting. Again it goes back to my point.. if it ain't happening to me....