I'm not sure how one knows "God told me to". We simply weigh the circumstances, we pray about it, and then move forward trusting God to guide our steps. Sometimes we make good decisions. Sometimes bad. But they're all from God who loves us enough to guide us into situations for our benefit or to His glory.
"The lot is cast into the lap, but its every decision is from the LORD" (Pro. 16:33).
Every decision we make is from the Lord. Good or bad. He guides our footsteps. Why we need to tout "God told me to" is beyond me. Instead we should be asking ourselves whether our hearts are deceiving us. But even in our self-inflicted deception our loving Father will teach us something from it.
I suppose I could understand this if Ratzinger had simply said, "I felt this was what was best for the Church, I prayed about it, and I felt peace from God on my decision. Now I'm trusting God that He will grant His grace and mercy to those who are affect by my decision."
First, we don't know what Ratzinger "simply said," because there's not a direct quote in the whole account. It could have been said ---as simply as you said!
Second, if Ratzinger really did feel an extraordinary grace and peace, understood as a call from the Lord to seek Him alone in deeper and more intimate prayer --- what can we do but rejoice? No shrugging or belittling for us, which might be hints of skepticism or envy: we are just glad that that this good old man, in his 87th year, has the call, and the opportunity, to devote himself to prayer in such a simple and all-absorbing way.
Blessed be God!