Sure you can. It has nothing to do with insisting they do what you want, it has to do with insisting they be honest and fair.

Look, if a guy my daughter is dating confides in me his devout love for her, and she tells me she doesn't really like him, but "since he has a cool car I'm not going to break up with him", I will feel just fine telling her to "Grow up", or "Man up" or "Woman up".

To me they all mean the same thing and it's not my fault our language doesn't have a good word that means both men and women. I suspect some other languages do, but "Human up" just doesn't have the right ring to it, and "People up" is even worse.

I think "Men" could work in a non-gender way ("Men up") . We'd have to use "Mans" as a plural if we did that I suppose. That's okay though, "Man's" is seldom used anymore anyway, unless it's in a past tense