Many people, including Pope Benedict himself, were brilliant and conservative, but not very good at personnel decisions. They belong to the George Bush School of Gentlemanship - never remove or punish your enemies, just to prove how fair-minded you are and in hopes that if they somehow get into power, they’ll treat you well.
It backfired on Bush and it backfired on them, unfortunately; Bergoglio was one of Ratzinger’s severest critics, from his dysfunctional Argentine archdiocese, and the Pope should have removed or demoted him (particularly when he attacked Pope Benedict for the Regensburg lecture). And Bergoglio has been ruthless with what he perceives as his enemies, the “conservatives,” and has actually removed a number of conservative bishops worldwide.
This is one of the reasons why I do not see him, Pope Francis, being Pope after another 2 or 3 years. He is not young for one thing and I think he has only one lung. The burdens of being Pope will even tire out even a Bergoglio in time.