I’m glad NBA player Jason Collins has publicly announced that he’s gay. But I’m already sick of hearing how “brave” that was. A main reason professional sports (especially male team sports) have remained a bastion of homophobia is that gay players have failed to show leadership by coming out and insisting on acceptance. By coming out, Collins is fulfilling an obligation to lead -- belatedly.

Unlike the military, sports teams are not bureaucratic enterprises where attitudes can be changed by orders from above. Instead, they will have to change the way broader society did: through gay people making themselves known to be existing, nonthreatening and valuable. Yet it took until today to have even one out male professional athlete in major team sports -- and we may not even have that. Collins is a free agent who hopes to play next season, but might not. So the NBA could still be looking for its first out player.

Did Collins have to wait until his career might be over? He’s a graduate of the Harvard-Westlake School in Los Angeles and Stanford University who has made more than $32 million during his NBA career. His coming-out story reflects the strong personal support network that’s available to him. Yet every day, much younger gays and lesbians routinely come out without such social, financial and emotional resources. Their actions are bravery; what Collins did should be expected.

Unfortunately, it’s not. Collins, for all his lateness, is still ahead of all his gay colleagues. And they’re probably not coming out for the same reasons Collins took so long: He says he waited out of “loyalty to his team” and not wanting his homosexuality to become “a distraction.” In other words, he was concerned about impacts on his career.

Those concerns were probably reasonable. But civil rights causes, including gay rights, don’t advance without personal sacrifices on the part of pioneers. Gay athletes will expose themselves to career risk by coming out. They ought to do it anyway because of the broader positive effects they can create.

So, we should congratulate Jason Collins for coming out, and hope that his announcement will make professional sports a more welcoming environment for gays. But more importantly, we should ask his closeted colleagues who remain: what is taking you so long?

(Josh Barro is lead writer for the Ticker. Follow him on Twitter.)