The upshot of those two posts is that the Reformation never would have occurred if Calvin would have just sat and been corrected by the local "parish priest."
I have no doubt that most parish priests whom Calvin talked to came away Reformers.
Of course there were reasons for the Reform movement beyond theology. The new era owes its existence to a confluence of three factors, the Black Death epidemic of the 15 century, absolute monarchies replacing feudalism and the Reformation. Both Calvin and Luther were able to form stable comminities of faith that persist to this day, despite the theological weaknesses. This points to the historical necessity of the Reformation, albeit not a theological necessity.