Good point, the fan themselves are changing. Some of it is corporate, but I also think a current "average fan" is now more interested in distractions (including but not limited to cell phones), than an "average fan" was 20 or 30 or 40 years ago.
But I do sometimes wonder how loud/crazy fans were, back in the 40s/50s/60s? The vintage pictures I see show men dressed in suits and hats, women dressed in dresses and finery. Were they all that loud and obnoxious? Were they reserved and refined?
Is our view of what a "fan" should be, limited by our experience, which is largely in the 70s-thru-present?
I think I went to my first college football games in 1965. We went to a couple of TU (U. of Tulsa) games that year. Jerry Rhome had been runner-up for the Heisman the year before, and the team had beaten Ole Miss in the Bluebonnet Bowl, so there was some juice around the football program. '65 was another good year, another trip to the Bluebonnet Bowl (a loss to Tennessee) and another Heisman runner-up in Howard Twilley. It's hard to recall what the fans were wearing, but I'm pretty sure that most people were not wearing blue-and-gold attire that they would not wear in a normal business or social environment. I remember that the band--which was small--wore black slacks, gold lame' jackets, and black derby hats. The Tulsa program went downhill later in the decade, and so did our attendance at games. The father of a friend of mine took both of us to the Tulsa-North Texas State game in Denton in his Beech Bonanza in 1967. I don't remember much about that game except that Tulsa got drilled.
Next college football game I went to was my freshman year at OU, 1972. I was in a fraternity and I sat in the card section. I generally wore slacks, white shirt, a red tie (or bow tie) and a sweater vest with a red "driver cap." Nobody, but nobody, was painted up red and white. One guy named Cecil Samara always dressed in red and white, and he was a sort of self-made celebrity for doing that, plus driving a red-and-white Ford Model T named the Big Red Rocket. The game was the focus. The fans were there to watch the game, not to get on TV, and TV did not continually pan the stands looking for goofballs. In fact, only one or two games a year were televised. There was no canned nose, musical or otherwise. except for updates of scores in other games and some announcements at halftime. No jumbotron telling us to make noise. There was cheering when things went well, and booing of the officials when they made bad calls (i.e., calls that went against us), but there was no requirement or expectation that fans were there to generate constant noise. One of the male cheerleaders, a few times each game, would lead the crowd in "When I say Red, you say White/When I say Go, you say Fight."
I think that there was somewhat more choreographed jackassery going on by the 1976 season. By about 1980, the card section was abolished because the students threw their cards in the air after they were done. Those cards were heavy, and they could hurt if they hit you.