Ayla is mine and she's sub only because of the nature of in which I designed her. I don't know what you've seen around here or even other places honestly, but people will bitch about anything. Ayla has very niche kinks, and submissive people, while still a majority won't like her, are less likely to create huge drama about it. I won't change my stance on her being a sub only character.
edit: In fact, go pack one page and read some comments about femdom and NTR. That is EXACTLY why Ayla is submissive route only.