And to advance a pro(re)gressive agenda.
I think that's the primary reason. The vast majority of racism/sexism/"homophobia" claims that make the news turn out to be hoaxes, leaving only very mild complaints such as the elderly gays in nursing homes who complain that they don't get as many family visits as those who had children get. The far left would have no evidence at all to support their agenda if they didn't make it up.