I don't know anything about your specific subject area but, yes, it's the cool thing about a Phd (or almost any research degree) - you are free to research any new area of knowledge you like.
You obviously have to research it objectively, follow sound principles around research approach, but otherwise free to test your hypothesis. If what you say is indeed true, then your literature review would uncover a tendency to marginalise an issue faced by males, and that is a good starting point into what you can prove is an 'under-researched' area.
If I may say, a PhD is a very long and difficult road - you have to be passionate about your topic. Sometimes it can be difficult to separate a passion from some kind of grievance, or in some cases a need to prove yourself right. For a Phd it doesn't particularly matter - the research itself has to be neutral and grounded in an evidenced issue. The issue is more about your own wellbeing and those around you - what will give you the motivation and drive to keep going? Good luck!