In the last 20 years, the "big hit", helmet to helmet hits and shoulder tackles have worked their way into the game to the point where almost no one uses a form tackle anymore. Form tackles don't end up on ESPN - those huge hits do, and that's what kids mimic, and those kids are now college and pro players. Everyone wants to see themselves on ESPN.
Harrison and his ilk are predators - he isn't looking to tackle, or even end up on ESPN - he is looking to put a guy out of the game. You think its a coincidence he keeps doing it to quarterbacks?
The game isn't softer by taking out predatory hits, its just re-emphasizing the types of tackles that were common place for the first 80 years of the sport's existence.