
All the discussion so far as I have seen...still does not get to the "why"/"because" or whatever rationale used to decide NOT to go with a good helmet.
As an example, I have a fellow Harley riding friend that a few years ago, had open heart surgery and a multiple bypass done. After that procedure, he was always "bugged" in a car/truck to have the shoulder/seat belt coming across his chest and buckled.

Now, that to me.......seemed to have some decent rationale behind it, due to his surgery. I don't think that is a problem to him anymore, and by the way, he does wear a helmet when riding.
In a similar vein, there may be some folks that have had a previous head injury or some prior problem that makes it painful or problematic for them to wear a helmet. In that event, it seems reasonable that they may choose not to deal with a helmet.
Where I'm going with this is........................"LOOKING COOL".

If one is choosing NOT to wear a helmet cause it (looks too big/makes them look like a space cadet)..........or their hair might get mussed up (helmet head)........or the Doo Rag and or backwards ballcap looks so much better..........
If any of the above examples or similar ones are your reason for not wearing a helmet, I would suggest you're accepting the potential to be tits up or drooling out the side of your mouth and not even knowing it.............all because..........Hey, I am gonna look cool at all times while I'm riding.