Whether they are well paid or not doesn't matter. There is a huge pie, they want their share and right now they do not feel like they are getting their fair share. There have been 3 lockouts in the past 25 years. All 3 times, the CBA was seen as a huge win for the owners. A few years later, the owners were whining about all the changes they made. The CBA as it is, they feel is costing them money out of their pocket. I get it, you like NHL'ers in the Olympics, or at the very least as a Caps fan, you want a happy Ovie. Secondly, for you to say they should have just extended the deal tells me you are not about both sides being profitable, you just want labor peace at any cost. I understand that as a fan, I don't want a lockout either. However, I am not going to put blame on the players when it is obvious the owners were trying to strong-arm them into extending a deal when they want changes.
Like I said, if extending the deal was out of the question on the player's side, they a counter-proposal would be a useless endeavor.