So, I bolded those guys who are still starting. That is a third of the list who still has a job. I also put in red those guys who are still playing. That is sixteen guys. That leaves thirteen players who aren't in the league anymore, and I'd say outside of Garcia, Pennington, Favre, Kitna and Warner the rest could still be considered playing age (maybe Garrard). What I take from this is that in 2007, there were a lot of shitty QBs in the NFL and now teams have turned to either better young QBs or the new shitty QB. Note that Leinart isn't on that list, as the Cardinals had already given up on him but should be thought of when considering bad QBs the league was leaning on at the time.
Here is a blurb from Cleo Lemon's Wikipedia page:
With Joey Harrington moving on to the Atlanta Falcons, Lemon became backup to the newly acquired Trent Green. With an injury to Green in Week 5, Lemon was named the starter for the Dolphins' away game against Cleveland. After shaking off some early rust, Lemon led the Dolphins to near victory against the Browns with several successful drives (including a drive where the Dolphins lost 20 yards on penalties that was capped with a 4th and 1 touchdown). Showing amazing determination, Lemon brought victory within their grasp, with his two touchdown rushes, two touchdown passes, and an impressive 107.3 QB rating, but the Dolphins' defense could not stop the Browns. His next start was in Miami's 49-28 loss to New England, going 24 for 37, with 1 rushing touchdown and 236 passing yards. But in Week 11, Lemon was replaced by rookie quarterback John Beck. Lemon was renamed the Dolphins' starting Quarterback in Week 15 against the Ravens. He threw a game-winning touchdown to Greg Camarillo in overtime to beat Baltimore 22-16, giving Miami their first (and only) win of the season.
I assume this was written by his mom, since "playing fairly well" is a 65 QB rating and he showed "amazing determination" in a loss against the Browns.