The thing is, sometimes those fanbases take pride in the fact their team hasn't won a Championship for a long time.
Look what happened to the Cubs. Finally get a win after 108 years and a few playoff appearances afterwards. Then they trade away the franchise this year!!! Hope fans enjoyed that WS win!!! Maybe another long drought?
Before 2004, the Red Sox hadn't won a World Series since 1918. Sure they've won a couple more since but it's turned Red Sox fans from lovable losers to arrogant assholes.
As a Ram fan, 1999 was unbelievable and it made up for the previous 9 years. But I was proud to be a Ram fan long before 1999 happened. I was proud of the Rams under George Allen. I was even more proud of the Rams under Chuck Knox. I was proud of the Rams under Malavasi when they LOST the Superbowl to the Steelers. IMHO, they gave Pittsburgh their hardest SB victory. I was proud of the Rams under Robinson too, even though they shat the bed vs SF in 1989.
You see, for me, it's about the game and the team. A Championship is the ultimate goal but not the only goal. If fans pin their hopes on a Championship, they might only enjoy it once in their lifetime. Some maybe never. I enjoy watching the Rams EVERY year because it has become a way of life for me. Some seasons are better than others. But it's always a joy and I'm proud to have been a Rams fan since the late 60's. And I've only witnessed 1 Championship.