The implication is that the original wasn't cohesive.

I think the real world sections of the original are perfectly cohesive.

Trying to put the thought in my head into words...Let's try this: Beetlejuice has an excuse plot like a lot of video games do. The plot is a framework to attach fun and amusing scenes together. It's an excuse to go to the ghost DMV and to have the dinner and seance and wedding scenes.

At one point they do have a stated goal of scaring away the Deetzes, but they don't achieve this goal. They scare off Otho, by making his...suit less trendy? Am I remembering that right? But the Maitlands and Deetzes end up living in harmony, Lydia gets the movie's victory lap. Beetlejuice is the title character, but he's really the closest thing the film has to an antagonist.

Really, the characters and plot don't matter as much as the series of fun and interesting scenes. That's why I enjoyed the movie; it's built more like a haunted house than a feature film. It's a series of loosely related vignettes. And if those are fun, then mission achieved.