Go ahead, do your study. You'd probably find that most hospitals have a slight preference for male nurses as they're trying to increase their diversity for all the practical benefits it brings. (Yes, diversity has a lot of practical benefits. Having people with a lot of different backgrounds around significantly improves the odds of having someone around who can successfully interact with a person no one else can.)
So if hospitals, theoretically, have a slight preference for male nurses in hiring right now... Why are they so uncommon? Because there are fewer candidates.
Hiring isn't "the problem". No one thing is "the problem". There's no bad guy to blame. No evil cabal. You don't need to get upset every time someone points out a systemic bias.
You aren't being accused of anything. You aren't the bad guy. But it would be nice if you acknowledged things are a bit out of whack, and helped to reduce the skew in the next generation. You don't need to fix it. It's enough to occasionally point out things could be better.