The problem was your lockout, which was based on greed, nothing else.
Prior to the lockout, you had a reasonable following in the U.S. (about as well as could be expected), but during the lockout, no one even cared that hockey was gone. I'm a fan, but not a hardcore fan, and I'm perfectly content playing NHL 'xx on my PC.
It's going to take at least a few more seasons to win back the blue-collar fanbase here in the States.
Good luck with that.