Me? I think of tanking as a strategic plan to make a football team better.
Teams could just forfeit games. But they have a role in the league to play the game and deliver a quality product. Not just show up and throw games by intentional poor play or coaching.
Trading off development of players is fine, IMO. That's legitimate part of long term team development. But if they're on the field, they should be playing hard, and the coaches should give them plays with the best chance to win.
It's a continuum.
What Jimmy did with sitting all the vets he traded the Vikes for was arguably over the line. He threw the season by keeping better players on the bench not for development of the other younger players, to but convert the vets into draft picks.
Playing your part in an institution *faithfully* has to be more than just not violating the rules. You can never write enough rules to enforce the spirit of rules, and the spirit the joint venture of the institution.