That's the problem with this debate.
It is not apples to apples if you go back to before 2011, because you are operating under entirely different rules and circumstances and amounts of compensation. Player salaries have skyrocketed WAY WAY beyond inflation. Not complaining about that; just stating a fact.

In 1980 the players had practically no means whatsoever to seek a better contract than to hold out.
But Donald has one year left on his contract (this year) and had he only reported when he was supposed to the last 2 years, he would have been a UFA.
And yes, under the same agreement he could have been tagged. But a player who is tagged plays under a different circumstance than a player who is under his 1st contract.

If one wants to argue that the system is unfair, fine. But the Union agreed to it and that is the system until a new CBA is negotiated.
Why should a team play within the ethical rules if a player is not required to (in the eyes of many players, agents, and fans)?

But not in the eyes of this fan. A player has an obligation to fulfill his contract. After that, his options change. I can even understand refusing to sign the new contract under the TAG and holding out for a long term deal. But refusing to play under a valid and current contract? No way.

Suck it up Aaron Donald and do what is right. You are being a bad example to those youth who look up to you. Why should they honor their promises if you won't?