I honestly cannot see what's the problem with playing just female chars even if you're male o.o
I'm a girl (25y/o mind you) and a gamer. For years I've played online games and single player ones. Countless times I saw myself forced to play a male character because of:
a ) gender-locked classes (LastChaos, hosted by Aeria, is one of many examples).
b ) unique-gender class (Forsaken World is an example of this, having some classes being female-only or male-only, while others can be either).
c ) (for single player games) the main character is usually male (with popular female examples being Tomb Raider series).
d ) FPS games, usually always male "chars", unless you have the possibility of a "female-looking" skin (hello WolfTeam?)
e ) MOBA games, you select and play "heroes" whose gender cannot be changed (DoTA, League of Legends, Smite, you pick).
And I don't complain o.o Heck, I don't recall many people complaining about it.
Sure, it sucks not being able to choose what gender is your character, especially in MMORPGs, but if there's games with gender-locked classes.. what's the problem with Scarlet Blade being all female?
Unless, of course, someone has issues with some boobies~