I disagree. There is a large disparity between a team that is genuinely putrid and one that simply can't get over the hump to win a championship.
Playoff appearances in: 90, 92, 94, 95, 97, 98, 99, 00
Playoff wins in: 90, 92, 94, 98, 99, 00
Since then: just TWO playoff appearances, both blowout losses in the first round. There's a massive disparity between going to the playoffs 8 out of 11 years (with six wins) and going to the playoffs in 2 out of 20 years, with ZERO wins.
The Dolphins in Shula's last years and during the JJ era, were not a championship caliber team, but they were a GOOD team.