Why is being a male feminist frowned upon in our society?

I am not sure that being a male feminist is frowned upon by society. I can perhaps hazard a guess that it might be because feminism has always been a movement by women for women.

I personally do not see anything wrong with men helping the feminist movement to make progress so long as they understand how their gender can limit their understanding of certain womens’ issues. By this I mean a man will never be able to understand what it is like to give birth, go through menopause, or be viewed as worth less in the workplace when doing the same job.