Something I should add. What you're saying, if I'm not mistaken (and if I am, please feel free to correct me), is that liberal theology is a consequence of the Protestant Reformation. I don't think this is the case.
Now, to be sure, liberal theology within the Protestant church can go unchecked or even be sanctioned, whereas the Pope has never sanctioned liberal theology within the Catholic Church. However, this has not stopped liberal theology from creeping in by way of some parishioners and even some priests (particularly in the Americas).
One might claim that the theologically liberal strains of Catholicism are a result of parisioners adopting some tendencies of liberal theology from Protestants. However, liberal theology as we know it today does not come from Protestantism. It comes from Fascism. The attempt to "purge" Judaism from Christianity left a permanent scar in the Western Church, and very few--if any--denominations can say that they have escaped the sickness of liberal theology completely. (And Papal loyalty or disloyalty didn't have much to do with the influence of the Fascists; the "German Christian" movement contained both Catholics and Protestants.)
You can agree or disagree with the Reformation, and we can argue about whether it has been good or bad for Christendom as a whole. But the Reformation is not responsible for Gene Robinson and the other joys of liberal theology. Did it extradite the process? Possibly. But the real culprit is Fascism.