The people who think this movie was "sincere" and "had heart" are being fooled.
If Sony actually felt that way, then this is the Ghostbusters movie that would have come out in 2016. This is a desperate Hail Mary to make something that addresses fan complaints from the movie they actually wanted to make but the fans hated, to try and get Ghostbusters fanboys back on the team so they can keep pumping out more Ghostbusters shit.
Sony may have funded the movie, but Jason Reitman is who actually made the movie.
Sony did try to cash in with the remake, but because it failed Jason Reitman was able to have the chance to do what he wanted and because he's a filmmaker with actual talent (Oscar nominated back when that still meant something) and for whom Ghostbusters actually means something, his literal dad directed the first two movies, he was on the set as a kid and actually acted in the second movie, if anyone would have actually cared about this ip it'd be him.
He was sincere in making a nostalgic homage to Ghostbusters and Harold Ramis, like I said it's not a cynical movie, so if you are a cynical person, it's not going to work for you, that's fine, doesn't make it objectively bad though.
The fact that it didn't take a cynical approach though is one of the things I like about it, I honestly think it's a small miracle this movie exists and I'm glad it does.
The movie definitely has some flaws, for example they're totally right that the brother character is a bit bland and could have been a deeper character sure, but I think one's overall response to the movie is whether one can still lose themselves in that childhood fantasy of ghost hunting, I honestly feel bad for the RLM guys that they're not able to do that, but I also understand what's made them that way, which is why I can sympathize, I'm not mad, just disappointed.
I hate to say that this is just a case of them simply not getting it, but well... they just don't get it.