PA, that sounds a lot like the sorry song of "if you ain't military, you ain't nothing." Hopefully that tired saw won't rear it's ugly head.
The FO was wrong. Nobody here disputes that. You may be right that a certain level of disrespect, and certainly a certain level of inexperience, exists today. the cockpit enironment is not the same today as it was decades ago, and that's a good thing. Inexperienced pilots have populated cockpits for many, many years; this isn't new. The environment today provides for a greater latitude for input by each crewmember, as opposed to the kingdoms and dictatorships that pervaded cockpits of old. Brashness in youth isn't new. There's nothing new here under the sun.
What is needed is a clear lesson in the chain of authority so that the F/O who misunderstands, is brought to comprehend his role. He should speak up when he has a concern. He should be assertive in his input. He should not hesitate to do his job. His job does not include taking charge of the flight, and should always be equally receptive to the captain for input and instruction; particularly when it's his leg.