I understand in fans' eyes you're only as good as your recent games. And Jesse's game declined towards the end, but a part of the blame has to go to McLellan, too. Last spring that was almost a concensus here.
You can blame me for overselling Jesse, it's okay, but by the end of 2018 he'd played 22 games and scored 8+3 in them. He was also +9 and his goal production rates were among the best in the NHL, despite him not having any PP time at that time.
The problems started later, and I believe McLellan had many tools to prevent at least some of it. At least he could've done something to feed his confidence, whether that's keeping him longer with players that he'd synced with, using him properly on the PP or not putting him to the 4th line on his wrong side.
I've read e.g. about the Jets, where some young players have said they've loved the way they've been allowed to grow through mistakes. I hope a combination of Jesse developing, speaking better English, and the new assistant coaches brings a better combination and this time Jesse could go on like he started the last season. Now I'll step aside (from writing) for at least a few weeks again.