The Cleveland Cavaliers‘ inaugural season was in 1970-71, when the expansion team would only go 15-67, and they would have a few more very rough seasons following.
They would gradually turn things around, though, thanks to players such as Austin Carr, Bingo Smith and later on, Jim Chones and Dick Snyder, but a good amount of credit for the Cavs eventually making the postseason three straight seasons (1975-76, 1976-77 and 1977-78) was Cleveland’s first head coach, Bill Fitch.
As was also displayed later on in his NBA head coaching career, along with at stops at colleges such as Bowling Green and Minnesota, was that Fitch would be more than willing to take rebuilding situations head on, and in the NBA, especially, he would succeed, and being in rebuilding scenarios a few times, let alone a bunch of them, is not something I would imagine most head coaches (or assistants, too) would be willing to participate in.