I think there are a lot of parallels in motor racing. Look at the cars from the 60/70s we are all in love with... 906, 917, ect... even look at the street 911 itself. There isn't much there. When people crashed hard, they tended to die. So folks didn't race like asshats pushing others around.
Now days (looking at you nascar), the safety equipment is so good, you can walk away from Armageddon. I think that drives folks to 'adjust the level of prudent' and race much more aggressively. This then becomes the 'new normal'. Wife puts it best...she's a critical care nurse for 30 years. Todays med surge patient was yesterdays critical care and todays critical care was yesterdays dead.
IMHO, same with young folks football (and to an extent pro). Better equipment allows a player to hit harder for longer. You don't have to maintain a reserve to make the whole game. Like racing distance events. The engineering is so good anymore its a 24 hour sprint. This level then becomes ingrained as 'what's normal' and everything is amped up.
Going helmetless has been discussed before...so that folks think and are more careful about what they do/try.
https://thinkprogress.org/could-getting-rid-of-helmets-actually-make-football-safer-75393ffe5c32#.v6xn7ps6t
https://www.washingtonpost.com/opinions/ban-helmets-during-practice-to-make-football-safer/2016/04/22/f72f7d2c-0628-11e6-b283-e79d81c63c1b_story.html?utm_term=.a63910b5c800
Current, former players suggest doing away with football helmets | NFL.com