Here is the thing that absolutely doesn't make any sense to me at all.
If a player loses their helmet, why do they have to go to the sideline for a play? Has their been any statistically proven study ran that indicates that said player has a higher chance of getting a concussion ONE play after they lose their helmet?
I understand that the rule is for player safety, but I don't understand how sitting out for one play after your helmet comes off decreases the likelihood of receiving a concussion.
If I may be so bold to explain what I believe they're thinking...
They've essentially clustered every instance of a helmet coming off into one category - removal by extreme force. Rewind back to 1995 against Kansas State - there's a famous punt return in that game where one of our players absolutely leveled a KState player, removing his helmet due to the blow. The NCAA probably feels, in this situation, the player now has a higher chance of brain injury due to the blow being so heavy his helmet came off. I have no evidence off hand to support this, but it makes sense - people who get one concussion are usually more susceptible to future ones. It makes sense that a player getting hit really hard in the head, so hard that his helmet comes off, is at a higher chance for brain injury shortly after.
The problem, obviously, is helmets don't always come off in this fashion. Dozens of cases pop up every year of an offensive/defensive linemen losing his helmet because their opponent was a bit too physical with their hands, pushing the helmet off. This is a penalty but it's not always caught. Furthermore, a strap could come loose in a tussle, and then a simple tackle could jar the helmet loose.
They've put a blanket over this entire issue believing that it will solve the problem, but every instance isn't the same or an indication of brain susceptibility. Chances are it's going to bite them in the a$$ when it's abused.