The difference is the team vs the league. If a team doesn't want a player for whatever reason they can let him go. Like the Pats with AH. The team has to deal with their fans, and they decide whether or not to punish/fire the player.
The league should treat every situation the same because it should all be spelled out. Then if the public thinks the punishment is either too severe or not severe enough, and the league wants to change it, they can change it so it takes effect the next time something like that happens. Kind of like this,
"I am sorry about the Ray Rice situation. I agree the punishment should be much tougher, but this is the punishment the League and Union came up with in our CBA. I will be immediately bringing this back up in front of the Union and League so we can get much stricter punishments in place if this ever happens again. I can only speak for myself, but I never envisioned something this awful happening when we worked on the punishments, it has no place in the NFL and I will work tirelessly until we have suitable punishments in place to keep this from ever happening again. I will remind the public, that while the league has strict punishments in place, that we have to follow, per the CBA individual teams have many options available to them including suspensions and terminations. "
Wouldn't that have been much, much better than what actually happened?