The worst part was the fast forward twenty years.
I know some people liked it - there were Diana and Kelly alive and getting along and they still had their parents and were friends with the triplets and the Grimm family legacy was being continued. (If it was unclear how Renard figured in Diana's life, well...).
My problem with it was that previously anytime you had seven people going gathering weapons to go kill monsters, there was a horrible situation. Maybe they were energized with a Grimm determination, but it felt different.
Stretching way back to the first episode, the Wesen that attacked Nick's Aunt Marie was his first kill as a police officer. I remember Renard asking how he was doing. Nick was soon to encounter many more situations where he would have to kill, and where the official police report would not be accurate, but at the time he still valued both human and Wesen life.
It was clear that some of that came from being a cop; that gave him access to solutions that his librarian aunt didn't have. It may be hard to remember that far back, but it made the expansion to his world a better one. Monroe and Bud became friends. The entire Eisbieber community brought Nick gifts and pies. Initially every Wesen who saw him was scared, but there started to be ones who heard of him, and knew could be trusted.
I loved that. The series really started taking a dump on it.
Even when it would look that they were starting to realize Nick was getting too callous, the solution was a comedic death, like the Alpe falling and fatally hitting her head. Beyond that, for that episode alone the hotel manager probably didn't need to die. The guy who tried to help the first victim certainly didn't need to die. A simple assault could have still gotten police intervention. Technically the other Alpe victim didn't need to die either, but I suspect people found the loud woman dying humorous as well.
One of the many dropped plotlines was that while in a zombie-like state Nick killed a guy. Renard accused Nick of only caring about killing non-Wesen. At the time I thought Nick's real problem would be that he was not in control. He had made conscious - if fast - choices to kill before, but not having been in control would feel scary and open the door to future concerns. The series direction really ended up being more that Wesen lives don't matter.
In one of the earliest Grimm comics, Nick encounters a hot Grimm in Europe. Maya's early family outings consisted of killing monsters and then ice cream, until this got her orphaned. Based on the premise of the Grimm world that is clearly one way of doing it, but Nick was finding a better way. You would think that after all he overcame, that would be reinforced, but maybe he just turned kind of negative and decided the family that slays together stays together.
You could still say that it's just a television show and question whether it is worth spending three (or possibly more) posts on it, but it matters to me as a writer and a human, and kind of in the same way.
Not caring enough about people can totally lead to plot-driven instead of character-driven stories. That does tend to make story-telling worse and betray the audience's investment in previous events. That is something I think about.
And, I don't really believe that anything is "just" entertainment. Maybe some things have less impact, and it's easy not to think about, but I do think about it. When so many messages in the non-entertainment media are about how many people don't matter, and who doesn't get to matter, that attitude needs to be rebuked.
One weakness of the show all along is that it did ascribe various traits as inherent to different types of Wesen, so maybe it was always on kind of shaky ground anyway. There was still a time when it was doing a lot better. Because of that I saw it through to the end, but now I am relieved that it's gone.