If the best that can be said of Franco is that he brought about the demise of his own regime it is hardly high praise.

Still, I maintain my original point: Franco appointed Juan Carlos as a successor to continue his regime, not a caretaker to oversee the transition to democracy. Clearly he did not choose very well since his successor promptly disbanded the regime he had been appointed to run. You are alleging good intentions where in fact there was only incompetence.