I personally can’t ship and will never condone Nick having a romantic relationship with Adalind, because she raped him at the end of season three (and in general has done nothing but harm and seek to harm him and those he cares about since the day they met). I don’t ship him with Trubel either, because they’re at least ten years apart in age, she’s very young (like 22), and he’s her mentor and in some ways her rescuer…it would be a power imbalance that I just couldn’t get over, and Trubel wouldn’t be in a position to give good consent under those circumstances.
And honestly I think it would take a very long time for Nick to come to a place where he’s ready to move on from Juliette. I mean…they were together for years. He loved her. He wanted to marry her. They saw each other every day, and were an integral part of each other’s lives for a long time. Not to mention he will probably always feel at least partially responsible for what happened to her. She was killed right in front of him, and she died drowning in her own blood, in his arms. That’s not something you get over really quickly, and I hope the writers realize that and give Nick the time he needs to really heal.
Not to mention, just from a personal perspective, I could definitely use a break from all the relationship drama on the show. There’s so much actual, interesting plot they haven’t even touched on. What about the keys? The coins? All the dire things hinted at in the first season and throughout the subsequent seasons, to do with the royals and the structure of the Wesen world, and the reasons Renard wanted Nick on his side?
For that matter, what about Renard’s entire character arc and all the stuff we don’t know about him yet? His hidden motivations? His ties to the Resistance? Oh yeah, hey! What about the resistance! And what’s going to happen with the royals now that–as far as we know–the entire line has been wiped out except for Diana and Sean? The last thing this show needs is another season of supernatural pregnancies and magic-fueled breakups. There’s plenty of plot to go around, if the writers will just use it.
Then there’s the fact that Nick’s dual jobs are both, on their own, not conducive to healthy, stable relationships. Being a homicide detective is a hard, dangerous job with long hours and constant uncertainty. That would put strain on any relationship, without the added layers of danger, duplicity, brutality, and secrecy being a Grimm brings to the table. I don’t see Nick just up and meeting someone who’s willing and able to handle all of that, who he’s willing to trust and get close to, any time soon. The odds are against him.