"...let's not sugar-coat the fact that Rosier was the worst QB to play at UM since Kirby Freeman..."
From one context, a basic reading is that you established two points in time, Kirby - Rosier. Fair enough. I was merely making a deeper inference that your starting point (Kirby) is incorrect. Overall IMHO, Costa and Collins were worse than Rozier for reasons to long to list here. Suffice it's my eye test as I'ven seen all three play extensively and you very likely have not.
I'll go even further with some of the OGs on this board who saw pre-Kelly QB play and I'm certain there are worse examples than Costa-Collins from those eras.
Also...had Miami even won that game against Nebraska, HIGHLY UNLIKELY the Canes crowned as Nat'l Champs that season. Also re: Costa, the Wash Huskies say hi.