Cows get bigger,
A comparison is learning to drive. People are taught to drive in normal conditions but are not taught to handle a car. All is fine until one day they get into a skid and carreer off the road out of control.
In the driving course I would add skid pan training so that drivers can be comfortable with understeer oversteer drifts locked brakes etc.
In the same way in flying a pilot needs to be comfortable with handling an aircraft in all its guises.
Not just spinning but stalls in all configurations and fully developed, spiral dives (which can be a lot more uncomfortable than spinning) Vne dives etc etc etc.
In that way the pilot has to be better and more confident in handling his aircraft and knowing what it can do than someone who has never experienced the real deal.
Pace