Teams have reputations which can harm them, whether you want to believe it or not. AL Davis Latter Year Raiders ring a bell?
The Patriots are a terrible comparison because their frugalness is more about letting young hungry players replace aging vets. The Pats didn't have a long, public spat with their first round pick, while nickel and diming over some bonus money. The Pats do something every team does, and the players all know it's part of the game. Also, and I suspect you might be aware of this little fact: 4 rings gets you a little bit of leeway.
Whatever their reason for doing what they were doing, what the Chargers were trying to do was such a trifle as to be laughable. That amount of money, in the players hands for that much longer an amount of time, means more to the player than to the team. It's REAL money to him, it isn't to the Chargers. Well, it better not be, or they are in some real trouble.