I don't think that actually follows:
1. People are perfectly capable of caring for injustices they don't experience personally. E.g. men being interested in pay-equity laws not because it would benefit them, but because of a belief that they are necessary for a just society.
2. People are also perfectly capable of acting against their best interests. E.g. women being against pay-equity laws because <insert reason why women "deserve" to be paid less>.