A friend and I had a great discussion about that, argoT;
If I remember correctly, the idea was that one player who wasn't a QB could have a salary of exactly $250,000 which is exempt from the cap but the contract has to be 3 years....and it's a guaranteed contract.
The thinking was/is, a QB is already the most recognizable player on the team, and they don't bounce from team to team nearly as often as the other players. Teams need marketable players who fans can identify with in this league with such turnover. This would give fans a QB plus one other who is identifiable.
Also, this would clear $250,000 of cap space to then be spread over the other players. Perhaps, raise the minimum salary or something. Helps everyone involved.
Teams would have to be very smart when handing out that one franchise contract, as the player can't be injury prone, or they will be paid for 3 years and that cap exemption spot wasted during the length of the deal.
I think you'd see young star players with 2 productive years in the league and have already tried their luck down south sign a 3-year guaranteed deal, thus, potentially playing for the same team 5 years. Much better than the current turnover rate.
If teams can afford to constantly pay for coaches and GMs that have been fired while also paying current coaches and GMS, surely they can afford a set up like this.