Since cowl air intake was introduced I believe in the early 60's, My thought was it was more to retain a stock look, it wasn't illegal by the rules, it offered cooler air, was easy, it was always higher pressure area, and air had less dirt when then they ran dirt tracks, and made it easy to introduce "windshield washer fluid" on last lap, but not sure.
Reality check, that half the population is smarter then 50% of the people and it's a constantly contested fact.
