Please name me "tons of players...missed by everyone" after multiple years in the league. Does not happen. It's not as if he's slipped under the radar screen.
By tons of players being missed by everyone, I meant lots of players go undrafted, skipped numerous times by every team, yet turn out to be players. The multiple years criteria wasn't part of the original equation, but I'll play along since it only takes ONE example to prove you wrong if you're saying it does not happen.
James Harrison went undrafted, signed with the Steelers, was cut 3 times while bouncing on and off the practice squad, signed with the Ravens the next year and played in NFL Europe before being cut again, then signed again with the Steelers. 3 years after everyone passed on him, he would start 3 games, and 2 more years would pass before he became a full-time starter.
So you're wrong, it happens.
Wait, there's more!
Wes Welker went undrafted, signed with the Chargers, got cut, played special teams for the Dolphins before starting to emerge in his third season with 67 catches, which still didn't indicate what he would become. Also worth noting: we drafted P.K. Sam the year Welker went undrafted.
Antonio Pierce signed as an UDFA with the Redskins and got to start 8 games his first season due to injuries, but played very little the next two seasons before getting a chance to start again due to injuries. He would become a starter and captain on the Giants D.
Bart Scott went undrafted, played special teams for 3 years at a high level but didn't get a chance to play defense until Ray Lewis was injured, then became a full-time starter for the Ravens and Jets.
Jason Peters went undrafted in 2004, signed with the Bills, and then got cut (by the Bills!), back to the practice squad, then wedge busting on ST for a few years before getting his chance in 2006 and becoming a full-time starter and Pro Bowler.
Fred Jackson went undrafted, tried out and didn't make it for the Bears, Broncos, and Packers, then spent 2 seasons in indoor football leagues, and another season in NFL Europe before catching on with the Bills, where he would spend 2 more seasons as a back-up until becoming a starter.
Maybe you think it happens only at other positions, that it couldn't possibly happen at the most important position on the field, quarterback.
Tell that to Jeff Garcia, who went undrafted, spent 5 years in the CFL before getting a chance in the NFL, then going onto 4 Pro Bowls.
Or Tony Romo, undrafted QB who sat the bench for 3 years, at risk of being cut until Quincy Carter failed a drug test, then went on to 3 Pro Bowls.
Or HOFer Warren Moon, who went undrafted and spent his first 6 seasons in the CFL before 9 Pro Bowls and 3 All Pros.
Or Kurt Warner, who went undrafted in 1994, signed with the Packers, got cut, played in the Arena Football League for several seasons before getting his chance with the Rams, parlaying it into 2 MVP trophies and a Super Bowl.
I'm not saying it happens a lot. And I'm not even saying Tim Tebow is going to join the list of names above.
All I'm saying is yes, it does happen. Anyone who says otherwise is wrong.