@matana
The argument "girls won't be interested in it" can work, but only for certain genres. The number of women who will play Doom or Far Cry etc, because they add a female character can be counted on your fingers.
You also shouldn't forget that huge number of games don't have a protagonist or the protagonist is a box, ghost etc
Hmmm, trying to recount games I think you are right in that in the last like 6 years we've been getting higher number of games where the MC is a woman.
It's just Resources. Resources, the biggest reason on the "why not" of everything. If it didn't exist or was infinite- we'd probably be in a very different world.