I think it's just homerism at its finest...
Romo as the backup creates problems. Remember that old saying "if you have more than one QB, you don't have a QB". Every interception, every bad pass, every bad quarter, every bad game will cause roars by some calling for Dak to be benched for Tony.
I think the organization made their bed when they didn't put Romo back in when he was healthy from his injury. Had they done that, they could've let Dak sit until Romo retired or until Dak could beat him in camp.
Plus it creates a competition question in the locker room. Why doesn't Romo get the opportunity to compete for his job too?