@Belgiancadengineer,
Because as men, we're winning right now. You don't really need 'help' getting employment opportunities when you're already "on top". Nothing, afaik, is STOPPING men from becoming nurses. The couple friends that took that route had no trouble and never mentioned any barriers.
The goal is the removal of unjust barriers so that (ideally) the only issue is what someone chooses to become, within their abilities.
edit-to-add:
The EXISTENCE of a gender gap is not PROOF of unjust barriers. The existence of a huge gender gap, coupled with institutionalized sexism, widespread corporate misogyny, and a not-too-long-ago deliberate oppression of women IS, however, a mounting pile of evidence showing that there are barriers for women to succeed based upon the same criteria men can succeed.
Oh, and of course, the uphill battle of fighting the denial and scoffing of people who just don't want to admit there are problems.