I don't agree that suspension with pay is not punishment. It clearly is. The natural state is to participate. No cop wants to be administrative leave, and no player wants to be removed from the team.

Not being on the active roster affects bonuses and accrued seasons, which affects the FA clock, advancement of contract years and retirement packages. It also can affect contract negotiations if those are on the near term horizon. Taken to court, I don't think it stands because each of those other issues have been negotiated in the CBA and you can't modify it without negotiations and an agreement unless the CBA has come to an end.

Suspension with pay should only be temporary and used in extreme cases (where another life has been put in jeopardy or such) and allow the League to do due diligence.

If the League has done its investigation with the player in question, it should move to suspend him for a term agreed to with the NFLPA (based on predetermined scales) if they have corroborating evidence. To move to suspension with pay after an investigation is just kicking the can down the road and there is no credit for time served.