It is truly amazing how you so vociferously introduce examples that totally discredit your assertions. You are also amazing wrong on several of your "facts." NBC paid Nebraska Public Television for its logo because the two logos were virtually identical and because NBC and Nebraska Public Television are both television networks. It was a terrible embarrassment for NBC and a windfall for the cash-strapped public network.
I didn't say it wasn't an embarrassment, I said it was a sideline. Whatever the payment was (I don't think it was in the millions) it might have been an embarrassment, but all the talk was about what a stupid logo it was. The Nebraska thing was just frosting on the cake.
As the point that you seem to have so much difficulty grasping is that NBC kept the Nebraska N unchanged for another four years. That was hardly a rush to chuck it. You also seem not to have a clue as to why it was modified. It is not modified for a reason, but for a personality.
Four years is not long compared to the CBS eye or the ABC ball, which have had minor changes by comparison. When NBC changed again, they also did not make a new variation on the sterile "N," but went back to the peacock (sans interlocking single line logo). Just because the change was done by Silverman, that neither means it was non-rational, without reason, or done simply to establish turf (Silverman already had the cred to not worry about that).
Fred Silverman was not just a personality. At the time he was considered a television guru. Apparently a man who had so much success in the field thought it was a stupid logo, too, and replaced it with what could have been considered a natural progression from the previous animated peacock.
And you compare this with New Coke. The example discredits your premise. Six months after Coca Cola put New Coke on the shelves, it announced that it would bring back the old formula (actually a variation of the old formula) in the form of Coca Cola Classic. Within a year of bringing out New Coke, "Old Coke" returned.
New Coke, one year; Nebraska N, eleven years. Yet you seem to believe that they are comparable 🙄
New Coke was not pulled after one year. It lasted in widespread distribution until the death of Roberto Goizueta... making the moves after to reduce it further (it was still available under the name Coke II even a few years ago in the south, and may still be bottled in foreign countries today.) only after a new personality took over.
The only way the comparison is invalid is in that a formulation can kill a brand very quickly, while a bad logo isn't really capable of killing a network. NBC tried to work with it, but as I originally stated, it was DIMINISHED, just as New Coke was, very shortly after introduction, shrunk and put into corners ... disappearing from local affiliate test patterns, etc. They tried to see if people would get used to it. When Silverman dropped it, you didn't exactly hear a lot of moaning or witness a lot of hand-wringing over it. The response was generally positive. And of course, NBC itself would start to do better only a little later.