Well, the Kings were the best team in the league for about two-three years there, they just didn't manage to win a championship, once because the refs destroyed them, once because Webber's knee blew up. In a (now) 30-team league if you can be the best team in the league for something between about 1/17 and 1/12 of the time (by definition, league average is 1/30), you're probably doing pretty good, especially for a small-market team.
Here's a list of teams that haven't won a championship in the 35 years since the Kings moved to Sacramento:
76ers
Bucks
Clippers
Grizzlies (25 years)
Hawks
Hornets (v.2, 16 years)
Jazz
Kings
Knicks
Magic (31 years)
Nets
Nuggets
Pacers
Pelicans (+Hornets v.1, 32 years)
Suns
Thunder (+Sonics)
Timberwolves (31 years)
Trailblazers
Wizards (+Bullets)
Here's a list of teams that HAVE won a championship:
Lakers (8)
Bulls (6)
Spurs (5)
Heat (3)
Pistons (3)
Warriors (3)
Celtics (2)
Rockets (2)
Cavaliers (1)
Mavericks (1)
Raptors (1)
The list of "haves" is small, and the list of "have-a-lots" is quite small. The list of "have-nots" is big, and we're in it, along with 18 other franchises, 13 of whom have existed the entire time. Just 7 months ago, it could be said that fully 2/3 of the NBA had not won a championship since the Kings moved to Sacramento. It's not like we're the only team out there struggling to make our mark in the NBA. As bad as we've been, there are five teams (Clippers, Wizards/Bullets, Nets, Grizzlies, T'Wolves) who have a worse W/L% than us over that timeframe, three of which don't even have the small-market excuse.
Bottom line, if you're putting in the effort to be a fan of a small-market team in the NBA hoping for a "payoff", you've picked the wrong team in the wrong sport.