Why didn't NASCAR make drivers stay in cars before?

This is off of my normal topic but I keep seeing the USA Today post NASCAR has new rule to keep drivers in cars under yellow shared over and over this morning.  And people that are sharing keep putting why it wasn't a rule before I find interesting.  

Why didn't it happen before? Why now?  Because drivers getting out of cars and yelling as other drivers went by or throwing helmets or water bottles made them money.  It made them money every time people in the stands and at home helped make rivalries from those actions.  It made them money every time the videos were shared.  It made them money every time people talked about it and needed to see what was going to happen next.  So we as fans stopped it from happening before now.  We helped create an atmosphere where it was not only acceptable but cheered for when a driver got out and showed his frustration at another driver.  We may not have created it but we stirred that pot every time.  If a driver was booed for getting out of his car, instead of being cheered, do you think they would continue to do it?  No.  So fans share just as much at blame for creating an atmosphere where it was acceptable to get out of that car and vent yourself in that manner.  

So why didn't it happen before? Because the fans made it okay.  So before blaming everyone else on why this should have happened before someone lost their life, think about every time you shared or talked about what a driver did when they got out of their car.  In the end we made it okay.