Everything that exists in the public eye has at least one honest fan somewhere, I assure you. Most of the people that love Warrior Cats are young folks, elementary school age, to be specific. However, keep in mind that several adults enjoy taking a trip down memory lane or delving into "childish" worlds for the escape they provide. (Which explains why older fans of superman are pissed off by the dark and gritty reboot.) Also, talking animals are hardly a new theme, just look through your own favorite fandoms.
Point is, yes. People do actually like it. However, due to the conduct of the Warrior Cats fanbase on this site, the stories of that fanbase are currently banned. Whether or not they will be unbanned in the future is a question for the admins.