Let me start by saying that I am, historically, a Derrick Rose basher. It's not so much that I think he's a bad player, it's the standard stuff: he shouldn't have won the 2011 MVP, he can't stay healthy, and he is very possibly a disgusting person. His super-huge contract extension looks objectively hilarious in retrospect, he's never been a particularly good shooter, and his teams have never had much playoff success (thanks, LeBron).
However, for $2.1 million, I"m fine with him being a Cavalier.
The Cavs have a lot going on at the point guard position, considering the chaos surrounding - and probable departure of - Kyrie Irving, the underwhelming Jose Calderon signing, and the theoretical development of Kay Felder. Derrick Rose provides a guy who is at least an NBA level talent.
Let's be clear, Rose is no longer a top-tier player and hasn't been since his MVP season. He hasn't played more than 66 games, shot better than 31% on three-pointers (unless you count 10 games in the 2013-14 season), or averaged more than four rebounds since the summer of 2011.
But once again, he's only going to make $2.1 million next season. Find me a point guard who makes less money and is slated to play more meaningful basketball. If Kyrie Irving does get traded, which sure seems likely, Rose could conceivably be the starting point guard on a LeBron James-led team, making 13% as much money as Reggie Jackson is getting in Detroit.
Obviously, Rose's role will depend on what happens with Irving: If Kyrie gets traded, the Cavs will get at least one starting-caliber player in return, but there's no telling whether that player would be a guard/wing/interior player. That uncertainty allows Derrick Rose to be optimistic and, similarly, for Cavs fans to be optimistic. There is no pressure on Derrick Rose in Cleveland.
On the other hand...
What's the best kind of player to put around LeBron James? A shooter. Derrick Rose is not a shooter. Last season, Rose shot an abysmal 20% on catch-and-shoot threes, per NBA.com. While he didn't shoot a lot of three-pointers, the ones he did shoot were ugly. Rose made just 23% of his three-point attempts when there was no one within four feet of him.
While his role is more likely to be as a distributing, slashing player, it still bears mention that LeBron plays heavy minutes and whoever is on the floor with him is predominantly going to be an off-ball shooter or rim-runner. That leaves Derrick Rose in an awkward position. The two things Rose is worst at are slashing and spot-up shooting as an off-ball player.
Per Synergy Sports, Rose was in just the 21st percentile in the NBA as a cutter last year, albeit on a small number (55) of possessions. He was in the 20th percentile as a spot-up shooter, which was remarkably his worst points per possession (PPP) of any play-type. Typically the lowest PPP is in isolation. These are problems.
The future for both Cleveland and Derrick Rose is very uncertain. For Rose, this is a chance to prove that he's worth the big contract that he originally expected this offseason. For the Cavaliers, it's a chance to stabilize the soon-to-change-again backcourt.