Learning is a very complex process and what learning theories do is to help us understand how this process happens. Behaviorists have seen human brain as a black box.
Were we really born with our brains as blank slates? Were we all equal when we were born, and where we are now is actually determined by external factors? Do our actions rely heavily on rewards?
It is really hard to say "No" to all of these questions. However, it is not easy to accept that they are enough to explain the process of learning alone.
The idea that we were all equal when we were born and the environment that we were raised determined what kind of a person we are going to be is something that I would never accept. The closest examples are me and my brother. We were both raised under the same circumstances in the same house but he became a cardiologist and I became a teacher who likes to travel around the world. Interests might have kicked in at some point in time to shape our choices but I believe in the affect of nature; when we were born we already had certain capabilities and capacities to learn.
On the other hand, it is at least not fair to think of human brain as a computer as there are feelings which may be influencing the way we are thinking.
As a result, I think that the role of learning theories is not only to understand how we learn but also to enable us to find ways for improving learning. In that sense, no one learning theory is superior to other, and as we discover new ways to investigate human brain, we will have more clues as to how learning really happens.
Driscoll, M. P. (2005).Psychology of learning for instruction(3rd ed.). Boston, MA: Pearson Education.