Well, I'm bringing a factual argument to the table. I'm not going on a limb and saying, "Well, the NFL was more fun back then." Why? Because the Buffalo Bills and Dallas Cowboys had 15 Pro Bowlers on each squad? The way you'll want it, 3-4 teams should be heads-and-shoulders above the rest of the leauge, and then you'll have the rest. If it requires talent-laden teams to draw your attention, then you shouldn't call yourself a fan. Take the perspective of a Tampa Bay Devil Rays or a Kansas City Royals fan if you want to understand the other side of the argument, because that's what you'll want in the NFL, another form of college football or the MLB.
I want every game to be competitive, everyone to have a chance, and for different varities of winning teams every so often. Let me ask you an honest question: don't you think it's more interesting to have a wide-open field other than an odds-on-favorite. IMO, it is. Look at last year's college basketball tournament. Who would have thought George Mason would have been in the Final Four? No one, that's what parity brings to the table, and they made it very exciting along the way.
Under parity, we've seen the likes of the Rams fall to the Patriots, Colts to the Steelers, Vikings to the Falcons, Packers to the Broncos, etc. To say the on-field product has declined under parity is laugable.