I wonder if this has compounded the TBI and concussion issue over the years. I think sports medicine in general has gotten much better and the average player is probably bigger and stronger and thus able to hit harder than 20+ years ago...
I noticed this with the NHL. Players are way more fit resulting in a faster game with more brutal body-checking. That compounded with improved protective equipment has allowed players to have a lot less regard for others safety.
There was an awesome blog post about the '70s-era Broad Street Bullies and how "soft" they look if you're used to today's NHL: http://www.mc79hockey.com/2014/05/the-broad-street-bullies-w...