I hate when someone is having an issue with their photography gear, with lots of brickwall tests, moaning and whining, but ignore what everyone is suggesting or advising... all while it becomes very clear that it is user error rather than an actual issue. Even worse when they claim they have 40+ years of photography experience, despite not knowing how to use basic things on a fucking camera. Nothing is ever their fault.
I call these people "fumblers". They boil my piss.