I don't have anything to base this on, but I think people are not considering how long NFL OT games would last if each team had to go only 25 yards to score a TD. In college, there's a 6 or 7 OT game with a final score like 70-68 every few years. In the NFL, I think that would be a common OT score. You give 2 good NFL QBs a short field and tell them they need to score TDs, they will, repeatedly. If they enact the college OT rules, people will be complaining that the games are too long and that it threw their fantasy football league out of whack.
This isn't directed at you, but I'm tired of the "But Mahomes didn't get a chance in OT" argument. Mahomes had a chance, during the 60 minutes of regulation. Maybe KC should have generated at least 3 points in the first half and they wouldn't have had to worry about OT. And when does getting chances end? Take the Saints-Rams, for example. The Saints had the ball in OT, then the Rams did and they scored. The game was over, but should it have been? Shouldn't the Saints get another chance? And if they scored, shouldn't the Rams get a chance to answer? At some point, people have to realize that there are no more chances, the game is over and they didn't win.