Hey pal, Every airline merger that wasn't DOH is still being debated! Pan-Am/Northeast, Northwest/Republic, American/TWA, and let us not forget Piedmont/Empire, just to name a few!
I believe the misconception here lies in a gross denial of historical fact and the idea that every integration turns on its own merits.
What is appropriate depends on the circumstances at hand. DOH is neither a "Gold standard" for pilot integration, nor is it used more frequently than some sort of relative slotting. Truth be known, even simple stapling happens almost as often. SWA/Morris...AA/Reno...AA/TWA...etc.
There are plenty of DOH integrations that are still controversial, TWA/Ozark comes to mind, and makes me think about Delta/Western and even that you may have it wrong and Northwest/Republic were all actually DOH, but the controversy was over the conditions and restrictions. Look at it this way, had the AWA/AAA integration gone DOH, but the conditions were that the West maintaned a min fleet of 142 ( with no east min) and bidding right of first refusal to the first 20 post merger deliveries, and furlough protection for 5 years, the east would be screaming bloody murder.
I guess we were destined to debate, because, even prior to mediation the east was told DOH would not be appropriate our likely. Due to the circumstances of this merger, had the east gotten DOH from the arbitrator, the C&Rs would have been so restrictive they would be worse off than with the Nic.