I tend to think the season had three segments:
1-14 start (difficult schedule, injury to Trey)
18-19 middle (up to the all-star break)
6-24 after the break
It's that 6-24 I found troubling. Why the steep drop-off? I don't for a second believe players were purposely "tanking," especially those in their contract year. IMO, combination of assorted injuries, a normal let-down as losing continues, and the fact that teams fighting for playoff position turn it up a notch and start to shorten rotations. Normally, I'd say we can't expect the same type of drop-off from this team. But without a SG, who knows?
I completely agree about the 6-24 misery business after the All-Star break. Besides the factors you mentioned, part of me thinks that guys may have dialed it in to a point due to believing that Ty wouldn't be back.