One combination of rule change along with technology that I see helping is shock sensors in the helmets. If the problem is that players receive a number of micro-shocks instead of a small number of concussion level ones, I could see a rule that a player can have no more than a given level of shock (with a formula that calculates intensity of the hits with quantity, kind of like how radiation exposure is measured). After a certain level, a player would be required to be taken out of the game for the week/month/etc. This could probably be implemented at the highschool and college levels fairly easily, but I'm sure that it would take quite a while to develop the formulas needed to determine a safe level of hits x severity of hits.
This rule would only seem to encourage players to hit the best players on the other team as hard as they possibly can.
At which point the number of hits required to knock someone out of the game tends to decrease over time, the length of time during which a game contains the best players tends to decrease over time, and the desire of anyone to keep playing this game tends to approach zero.
Ah, that can be solved with penalties for bad hits, just like there is a major penalty for face masking. Also, from what I can tell, the major hits are helmet-to-helmet, so any purposeful infliction on one player may have an equal infliction on the other.
Also, I wasn't proposing that this would have an immediate effect of taking a player out of an in-progress game (actually, re-reading what I wrote it kind of sounds that way), but I was thinking more post-game analysis, where the cumulative hits to the skull determines a player's eligibility to play (similar to if a player had a cracked rib or fracture in the spine, etc).
The NFL is already perhaps overprotective of quarterbacks, because quarterbacks are bigger superstars than defensive ends and linebackers. Oddly, this is one of the biggest things actual fans complain about.
