As for restructuring, players aren't "throw(ing) away millions of dollars" - they're getting the salary they would have gotten sooner through a bonus and extending a few years out to knock the cap figure down.
That is not completely accurate. The future years of a players contract are not guaranteed. If their contract value in future years is now significantly out of whack with what the player would garner on the open market, then players will often restructure for less money in order to continue playing for their team.
For instance, we may value Beason higher than a team in FA would (given the injury). If we request to restructure his contract, the lower contract that we offer may be slightly higher than he would garner on the open market (but significantly less than the monster contract that he signed). In this case, restructuring would be for less money.