Why are Captains diverting because Flight Attendants are letting themselves get caught up in arguments between two passengers? Really?

Flight Attendants are not Peace Officers. If one passenger is ill behaved to another passenger, what role does the airline have in that, if any? Does an airline have a duty in such circumstance? If there is room in First Class, I say find a serviceman, or peace loving grandma, and move them, but the miscreant in the newly open seat.

Or, if flying Jet Blue, lock them in the lav.