This applies to many excluded groups. People hire from networks; if you don't make any effort, your network will be the status quo, which last from generation to generation. With a little effort, you can expand your network to excluded groups. From even a purely self-interested perspective, access to more talent and a more diverse set of ideas and experiences is never a bad thing, and being exluded means there is more undiscovered talent.

One simple method is to tell the recruiter that you want at least N serious candidates from excluded groups for each job. This causes the recruiter to also expand their network.