I sometimes wonder if the issue isn’t so much that Pixar never has any female leads (Brave notwithstanding), but that they don’t appear to be particularly well-represented amongst the more miscellaneous ranks. Several Pixar films have huge groups which all, by default, appear to be male, despite common sense frequently dictating that a few members would have to be female, for the purposes of said group sustaining itself.
Consider that:
None of Muntz’s massive army of dogs in Up appear to be female. We certainly never hear any female voices coming out of those collars, anyway. I’ve actually heard a bit of debate on the significance of those voices and those collars - does Muntz supply the voices himself or are they (Alpha’s malfunctioning collar aside), intended to be accurate representations of how the dog would sound if it actually could speak like a human?
It’s been a while since I’ve seen A Bug’s Life, so forgive me if I’m wrong, but, other than the passing reference to Molt and Hopper’s deceased mother, I don’t remember there being any female grasshoppers.
Were any of the scarers or their assistants female in Monsters, Inc? I can’t recall. (This is one group which would not, in itself, have to contain any females for the purposes of reproduction, but still, it’s interesting.)
One female rat, with one speaking line (“How do you know?”) in Ratatouille (but then, other than Remy, Emile, Django and, to a lesser extent, Git, there aren’t very many rat speaking roles - I know that Remy’s mother was originally intended to be a character, but got scrapped in early production).
Just an observation I’ve made. I thought I’d add it to the debate.