So I'm a big fan of the Cincinnati Bengals. That happened in late October of 2002, when they opened their season 0-and-7. I thought they had a chance of having the first-ever "defeated" season (what's the opposite of "undefeated"? "Unvictorious"), but on November 3 they routed the Houston Texans (of Houston Texas), and finished the season 2-14. It was at this time that everyone started pointing to the Bengals as the prime example of "the downside of parity". Cheap teams could be bottom-feeders, living off the league's largesse without contributing, or even trying. From 1991-2002 they went a combined 55-137, with zero playoff appearances, and since the owner showed no sign of selling, they were doomed to stay this way. In other words, the argument was: "parity is communism, and communism doesn't work".
And yet, just 3 years later, with the same ownership, the Cincinnati Bengals are AFC North Champions, with a 11-4 record. They haven't been dominant (2-3 against playoff-bound teams...which suggests a pretty weak schedule), but that particular "parity doesn't work" argument is pretty much shot. I suppose people can try to apply it to the Arizona Cardinals, or the Houston Texans, but neither of those would be anywhere near as convincing.
It'll be interesting to see what the next "parity doesn't work" argument is. I imagine someone, somewhere, is going to mention the Pats. Which is silly.