He doesn't want to live in the Apostolic Palace.
That may be partly true. More importantly, he wants to live as he did in Buenos Aires, and he doesn't want to be isolated. He likes to be with ordinary people.
He explained his choice in a letter written two weeks ago to an old friend, Father Enrique Martinez, a priest at the Church of the Annunciation in La Rioja.
"I didn't want to go and live in the apostolic palace. I go over there just to work and for audiences.
"I've remained living in the Casa Santa Marta, which is a residence which accommodates bishops, priests and lay people." There he feels "part of a family" he wrote in the letter, which was obtained by Clarin, an Argentinian daily.
"I'm visible to people and I lead a normal life – a public Mass in the morning, I eat in the refectory with everyone else, et cetera. All this is good for me and prevents me from being isolated.
"I'm trying to stay the same and to act as I did in Buenos Aires because if you change at my age you just look ridiculous." The Pope, the first Jesuit pontiff in history and the first to come from the Americas, said his election was "something totally surprising" which he considers "a gift from God". - Telegraph
I like that.
As for other bishops, especially brand-new ones like Bishop Michael Barber of Oakland, maybe follow the rubrics and stick to protocol on your first assignment.