Couple of points:
- In the beginning of Jay's run, he was consistently beat by Dave, NBC gave him a significant amount of time to build up his own tonight show franchise.
- NBC killing off all their 10pm shows to make room for Leno destroyed a ton of the lead-in audience, which directly effected Conan.
- It was Conan who was willing to walk away from the Tonight Show, had he stayed he would've both hurt the Tonight Show accepting the time-slot change and possibly destroyed both Fallon and the Late Night franchise.
- Multiple articles after Jay's return pointed to his ratings being pretty close with Conan's, with Letterman beating him for awhile. Leno's ratings did improve...but much of it after NBC rebuilt their 10pm programming block.
Jay Leno isn't a bad guy, but between him and Conan, which one acted in the best interest of the Tonight Show/Late Night/Fallon? Which one you think Carson would have sided with?