Spinoff: How did Norm not get to host "The Late, Late Show"?

I've come to the conclusion that Letterman wanted Norm fairly early on to take over his show once he inevitably retired. There was no bigger champion for Norm's career than Letterman. Now Norm has pissed off so many executives in Hollywood that it's nothing short of a miracle that he's still given gigs outside of stand-up.

But seriously, his only competition would have been Seth Meyers, who I'm fairly certain he'd curb stomp in the ratings. Yes Norm getting the Late Show was a long shot considering how divisive and defiant of authority he is, but in this day and age with a midnight slot, who cares what he would have done? Just bleep out anything inappropriate he did. The guy is in the top 5 of greatest guests ever as basically any talk show host who has had them on their show would say. He was always gold on any program he was on.

Instead they give it to someone no one knows named James Corden. Norm has been proven to be a popular draw, and I'm sure Letterman completely backed him to host the program after his own. Aside from maybe Robin Williams, has there ever been a talk show guest as good as him who has not had the opportunity to host a talk show (save his podcast of course)? Comedians and rival talk show hosts alike would be fighting to get on his show just to lib off of him being the host.

So is there any reason he didn't get it besides pissing off almost every entertainment executive? It's a no brainer that he'd get fantastic ratings and would be safe in the midnight slot. There is no other reason he didn't get that job that he would have killed. I also think this may have been a reason he was tearing up with Letterman, knowing he was chosen by him, but his own comedic genius fricked him on getting into Letterman's seat.