I for one believe that topping from the bottom is possible and usually in the case where the "bottom" isn't really trying to be submissive, they want the allure of being submissive without actually having to listen. So they manipulate the scene into what they by being disobedient or however they might otherwise manipulate their "master". To some degree I chalk it up to inexperience on one side and an unclear definition of what they actually want on the other.