What it means
Let’s get the obvious out of the way first: Crockett Marcel never lived up to the high standard set by Connor Rhodes, despite the best efforts of Dominic Rains. While Rains did an excellent job with the material he was given, Crockett as a character has yet to be as watchable or have the kind of impact that Connor did.
The biggest reason for that is that the writers have yet to fully develop his character. Audiences learned very little about Crockett over 20 episodes, with the biggest fact about him coming in the season finale (his having been a parent and losing his daughter). And as we saw with Dr. Ava Bekker (Norma Kuhling), when you don’t know much about a character outside of their connection to another character, it’s very hard to embrace that character and become a fan.
What One Chicago fans will remember most about Crockett this season is being the guy that came in and messed up April and Ethan’s relationship. Not anything about him, but what he did in other people’s story. That’s not much of a first impression. So the onus is now on the writers in season 6 to tell his story, and hopefully not by allowing it to be dominated by his future romance with Dr. Manning. Once we know who Crockett Marcel is, viewers might actually love the guy. But for now he’s a near-stranger.
The good news is they toned down on those “hard-partying” antics; aside from him using an ED bad to recover from a hangover, there weren’t too many instances of him being insufferable. So that provides hope that Crockett is headed in a more realistic direction, if he can get there in his next 20 episodes.