I’ll answer it. Luther was addressing his pope like this because he preferred his own version of the Christian religion to the Catholic Faith. The Catholics here who take issue with “Pope” Francis take issue with him because Francis prefers Francis religion over the Catholic religion.
Well the Catholic church at the time was selling forgiveness and executing those who opposed it, so... yeah I suppose based on that he did prefer “his” version of Christianity. Of course, “his” version of Christianity was merely what the Catholic church historically taught, which it was no longer teaching.
So there’s really no difference between today and then - both Francis’s detractors and the medieval reformers both argued that what the pope was teaching wasn’t Catholicism. The difference is that Francis is nowhere nearly as - dare I say - demonic as the some of the medieval popes.
Selling indulgences was an abuse (which is wrong), but that was not all that Luther revolted against. He revolted against Church doctrine which was always Church doctrine.
So you are wrong. It is not the same thing.