Let me get it straight: the majority of people that you have interacted with in your life determine reality? Really, are they mostly IU fans? Might that bias perhaps color their knowledge? And what knowledge do they have of the situation in the 1940s and 50s and 60s?
I note that you did not deny the point about only conference champs and no independents in the early NCAA. Ever hear of the McGuire Rule? Why did that come about?
By the way, the NCAA was not the only arbiter of basketball in those days. The AAU was also a major partner. It was not a monopoly as it is now. In fact, the NCAA bought the NIT rather recently because they could have been sued for monopolistic tactics by the NIT - restricting trade.
Do you ever pay attention to what you write? You posted that the NIT was more prestigious but that didn't last long? I guess "not long" is 25 years or so. And then you write that the winner of the less prestigious tournament, by your own admission, "...was still likely to be considered the best team in the nation." Do you not realize how ridiculous that comment sounds? There's no support for that other than your own declaration.
Then you dodge and declare that NCAA Tournament winners are and always will be THE national champions. Nobody is debating that as true in the present. recent past or future which is the tenses in which you are posting. The discussion was about the more distant past, and your commentary on that matter is absurd, and I am being charitable in that description.
And I also note that you ignore the historic religious bigotry that was a major factor in NCAA and university politics in those days. Ever wonder why religiously affiliated universities were ineligible for Phi Beta Kappa? Same as the reasons that they could not enter the NCAA.