Lue and LeBron love to give old guys minutes because they don't trust young players. We won't develop beyond this short window if younger talent (Derrick Williams/Felder) go under developed.
It's funny, LeBron will sacrifice wins to sit, but didn't seem last year to want to sacrifice wins to develop young talent.
I don't agree with this. The Cavs DID play Felder and Williams. Felder even got all the minutes he could ask for in Canton. He wasn't ready to play in the playoffs, let alone the finals. Most, if not all rookies typically aren't ready for a stage that big by the end of their first year. I'm not sure what else you would want from the coaching staff when it comes to Kay.
As for Derrick, he also got minutes and looked solid. Not great, not bad, but solid. Again, first year in the system, and he got squeezed from the rotation come playoff time, which totally makes sense. I highly doubt Derrick makes much of a difference in the finals if he gets minutes, though you could make the argument he was worth a shot. But at that point, you're just splitting hairs.
I'm as critical of the Cavs as the next guy when it comes to drafting and developing players, but does anyone remember how long it took Delly to get acclimated? He was really bad his first year. His second year, he was still pretty bad, but he had to play because of injuries. By his third year, he was a legitimate back-up point guard. It takes years for a player like Kay to get to a respectable back-up level, and that's if he even makes it.
I don't know what people were expecting from him and Derrick last year, but it's clear some had way too high a bar.