At least half the guys on your list are great for making the point you are trying to rebut. And consider that "seasons" doesn't mean much for NFL QBs, especially the guys who end up barely playing as backups or who keep getting injured. Peak behind the curtain at games played.
Keenum has 78 games played over his 10 years.
40 total games played (5 per season) for Tim Rattay.
54 games played for Rex in a career with more picks than TDs.
Colt McCoy's "12 seasons" in the NFL (which includes 5 seasons where he made less than 30 pass attempts), but where he played in 55 total games.
All of those guys played in less than 5 seasons worth of games, regardless of how long they managed to stick around collecting checks in a league with a dearth of QB talent. ****, even Vick only averaging 11 games played per season comes out to less than 9 seasons of games.
Kyler is good and still young, but the jury is out on how long his career will last and the impact he has. He missed 3 games in 2021, and 6 games last season. There's already a fair chance he misses games to start season 5 recovering from his torn ACL in December. If you are looking at maximizing the 5 year window, his seems to be closing at a bad time for AZ.
Wilson and Brees are undeniable talents with very successful NFL careers. And Wilson has been especially durable. He might be the exception that proves the "under 6'1" rule." Of course, you didn't include guys like Pat White, Johnny Manziel, and Cade McNown, all of whom (off the top of my head) were 6'1" and failed and/or nearly died in the league.
There is a reason so few QBs under 6'1" are drafted.