Major League Baseball used to be the most labor contentious league out there. Then they had a massive, multi-year fan backlash that resulted in big declines in revenue and attendance that lasted until the home run chase, which scared both players and owners alike.
Now they've had 20 years of labor peace.
Fans do have a voice if they're willing to not be taken for granted, and so far NHL fans have shown a willingness to come running back like it never happened. MLB fears the consequences of a work stoppage, the NHL doesn't.
For fans it is ultimately just a game, and a few hours of entertainment. How long can you hold a grudge when you're not really directly involved in the fight? We're not even little kids in the middle of their parents divorcing. It's just business.
Baseball did have many work stoppages. Maybe the last straw there was that a strike near the end of the season came at the cost of the World Series. The players gave up the one thing that they say they really want, a championship. Had the NHLPA strike in 1992 lasted long enough to cancel the Stanley Cup Final, maybe there's a different feel to everything that followed.
Add to that, from what I've quickly read, baseball didn't end up with an actual CBA until years after the last strike ended. That's just something that lingered on and on.
The NHL lockout in 04-05 cost the entire season, which probably in theory should come in 2nd to none on the pissed off fan barometer. Why didn't it? I don't know. Why didn't the lockout last year, with the PA bringing in the biggest gun they could, and the owners fresh off an entire lost season because of a lockout they started, not do it? I don't know. Every situation is a little different.