CRM should never be understood as any type of replacement for good manners, or reasonable social skills. CRM could / should be viewed as a living toolbox, filled with skill tools, and knowledge tools, to be used when appropriate.
CRM is simply a sub-element of the Human Factors subject, and as such, is something that we are expected to learn, consider, and apply on all flights.
A simple observation of the various conflicts (wars) that are going on around the world should be ample evidence that we don't generally get along ---as a rule---.
I fly for a national carrier with a fairly homogenous pilot group-culture, and even here we need to be very careful with some of our colleagues. That said... Not all of us find the same guys difficult.
CRM is a professional skill, and as such, it is most certainly not meant to water down the captain's authority, or command responsibility.
The captain stays the captain. It's just that now we have found a way to get through to those who are more ego-centric, as well as those who are simply normal...!
CRM does not replace manners or seniority (as in "experience").
Cheers
Pitch&Fan