Let's look at this real life scenario. Captain meets his first officer for first time and asks the first officer which leg he would like to fly? F/O shrugs his shoulders and says he doesn't care as long as he gets equal share..
Captain completes fuel figures and shows the total to F/O with the comment "are you happy with these figures?" F/O says no - there is too much fuel. Captain puzzled asks why there is too much fuel aboard. F/O replies that he (F/O) calculates three tonnes less than captain's figures. Captain then points out it is a tankering sector and that is why he has additional fuel aboard. F/O grunts.
Captain gives F/O the leg and during descent it is clear the F/O is behind the profile. Captain suggests F/O should take necessary action to get back on profile asap due getting close to airfield. F/O says he is working on it but does nothing effective except speed up and gain more energy. Captain gets edgy and suggests that best get the landing gear out to create drag. F/O says OK in a minute...Captain exasperated says gear going down NOW and F/O grunts. Aircraft barely attains a stabilised approach by 500 afl. After close down the captain asks the F/O if he would have changed his flight profile earlier given they were high from 10,000 ft downwards. F/O says "if you hadn't bloody interfered with my descent planning we would have made it in OK..."
And that is what happens when CRM becomes the catchword for everything.
So called CRM has destroyed the "old fashioned" good manners and respect that was once a feature of a well run cockpit.