Some of these teams went through so many years of plugging in whatever they could find off the QB scrap heap. When they find someone who at least has enough talent to stick around, they feel like they have to do whatever it takes to keep them there and not go back to the scrap heap.
Dolphins' starting QBs since Marino:
Jay Fiedler
Damon Huard
Ray Lucas
Brian Griese
AJ Feely
Sage Rosenfels
Gus Frerotte
Joey Harrington
Daunte Culpepper
Cleo Lemon
Trent Green
John Beck
Chad Pennington
Chad Henne
Tyler Thigpen
Matt Moore
Tannehill
Only Fiedler, Pennington and Tannehill even played one full 16 game season. Tannehill now has 3 in a row.
The Panthers QB with the most starts in franchise history is Jake Delhomme. Aside from him the guys they've run out there for multiple starts include Steve Beuerlein, Kerry Collins, Chris Weinke, Rodney Peete, and Jimmy Clausen.
When you have so much shit at QB for so long, when you see a glimmer of hope, you latch onto it. I understand too after the shit we ran out there post-Aikman. When I first heard Romo's name, I never would have fathomed he would be a ten year starter here. But when he first came onto the field in 2006, I was hooked.