This is something i spent years bitching about when Dawn Aponte was angling to set herself up for a new job at the league office. Its a dumb, shoot-yourself-in-the-foot "principle" on the teams part.
Its important to remember that picks after 15 (or something) automatically get offset language. Its something the players more or less conceded on. So any relatively successful team doesn't have to deal with this ****. And it goes without saying that should be the goal for every franchise.
How does royally pissing off your high draft picks over what is essentially nickles and dimes to a franchise help their chances of never dealing with this issue again? In the Chargers case its especially rough. Mike McCoy might be in the hottest seat in the league. Even if the front office doesn't care about that, that team lives or dies on Philip Rivers arm. Rivers turns 35 during the season. Even in his prime Rivers couldn't carry that team to a ring with bad defenses. Defensive ends usually take 2-3 years to fully develop. Its just not a position you learn on the fly. If he misses all of training camp the team basically eats an entire year of progress. And thats assuming he can ever recover from such a missed opportunity, which is no guarantee.
These young players are trying to set themselves up for life. And given CTE its not an exaggeration to say they might give up their life for this sport. Bosa and anyone else objecting to these shenanigans are not only fighting for their right to get the best deal possible but for the rights of future players. The NFLPA and agents have an vested interest in making sure their guys get all the money thats owed to them. On the flip side, whats in this for the teams? Less than a million bucks in the event he busts? If a team misses on the 3rd overall pick they have bigger **** to worry about than a couple hundred thousand dollars.
Of course, the above assumes teams are doing with honorable (albeit mistaken) intentions. They aren't. This is just another way the NFL has chosen to try and put them uppity peasant players back in their place.