Here is Pope Pius II (Aeneas Sylvius Piccolomini) reporting, in his Commentaries, the response of (then Cardinal) Nicolas of Cusa to Pius unilaterally appointing cardinals (quoted in Watanabe, Concord and Reform, Ashgate, 2001, p. 10):
The Cardinal of St. Peter (Cusanus)…Finally answered as follows: “…Now you ignore the ordinance of the synod and do ask the consent of the college and you wish to make me a tool of your ambition. I cannot do it. I do not know how to flatter. I hate adulation. If you can bear to hear the truth, I like nothing which goes on in this Curia. Everything is corrupt. No one does his duty. Neither you not the cardinals have any care for the Church. What observance of the canons is there? What reverence for laws? What assiduity in divine worship? All are bent on ambition and avarice. If I ever speak in a consistory about reform, I am laughed at. I do no good here…” With these words he burst into tears.
Luckily for Nicholas, he and Aeneas were old friends, so there was no excommunicating that day. Not everyone may find this grinworthy, but I usually enjoy a bit of schadenfreude at the expense of the medieval Church.