Honestly, and I might get criticized for saying it.. but I think the NFL rules contributed to this.
Defenders are basically handicapped in terms of what the can and can't do. One thing in particular is they can't launch themselves at "defenseless" receivers.
Even though that wasn't the case on this play, Damar was penalized earlier in the season for hitting a defenseless player. It forces you to hesitate. Hamlin was standing upright with Higgins launched his helmet into his chest.
The NFL passed a rule saying runners can't launch the crown of their helmets into defenders, but they rarely enforce it.
SO you can't hit the quarterback. You can't hit a receiver coming across the middle. A quarterback can wait until after you dive for a tackle to slide and draw a penalty. And Offensive players can launch into defenders, draw pass interference calls by running into defenders for underthrown balls constantly hold defenders and not get called 1/2 the time and all defensive players can do most of the time, is wait for a mistake.
The NFL wanted more offense and they got it. But at what cost?