Sorry, I don't get the idea of the thread. As far as I know every ATPL has to start from PPL, which means she or he does have to do typical around 40-60 hours in small aircrafts until PPL. So, I assume there always is a basic knowledge on how to fly a little plane.
Does a fully blown, full-time airliner captain need to keep flying skills for a little plane? I doubt that one. Yes, I know quite some flying big and enjoying little for leisure, but are they "better" pilots? I would not sign that.