I think Ubisoft's response is absolutely ridiculous, especially when other studios have said on many occasions "with the amount of female gamers coming to the market, any cost is worth it". Considering they've animated females in their games before, and have done so to an extent that surpasses some of their male roles (see Rainbow Six Siege), I think they just hate playable females plain and simple.
It's not hard to fault them when focus groups tell them they want a male character on the front cover though. Despite being crucial to the plots, both developers of The Last of Us and Bioshock: Infinite had to go to great lengths to get their female roles on the cover even if these characters were paramount to the story. But how many people remember "Remember Me", and how many touched on it because they weren't attracted to the idea of playing a female character? In a focus group most of the people there will say they want a buff male character on the front cover because it sounds better than a pretty young woman next to said buff male character, even if they don't mean to.
I welcome female video game characters and I try to get into them as much as I can, but when males have dominated the games industry making that transition to another gender is surprisingly hard. I don't want to see this young lady get harmed, even though in the games I play she can quite easily handle herself and was made to do so. Whether that's an effect of video games or some kind of sexual tension mixup I cannot say, probably the latter.
When it can be done with minimal resources (see CoD: Ghosts, Fable, Rainbow Six: Vegas and Blacklight: Retribution), you'll barely notice the difference. I mean, who's going to check every character and mock them for being female? This never happened in Rainbow Six: Vegas, and it doesn't happen now.
Either Ubisoft are so incompetent that they haemorrhage resources during development so they can't, or they're too pig ignorant to realise females are coming to the games industry now more than ever and would like to see themselves as a welcome addition but are too intimidated by the sausage fest that is Triple A Tripe.
I'd recommend you watch the Jimquisition about this, he's a brilliant - if vulgar - and while you may disagree, he's still entertaining nontheless:
Diversity? LIEversity - The Jimquisition of the Escapist.