Squabbling and infighting would have been fine. Even Holdo being an idiot and a martinet was fine. The problem I had was that the movie was trying to paint her as a selfless hero for what she did. She wasn't being humble, though, wasn't avoiding being seen as a hero. She was withholding vital military information for no good reason. All it would have taken was a line, a single line, where Leia and Holdo discuss that they're worried about there being First Order moles or plants among them and they have to be careful what they say. Just that. Just something to give a reason for the seemingly unreasonable, and she could have been seen as a selfless hero. That's lazy writing, because the writers really wanted to keep the information from the audience.