Rodgers has 10x the talent of Kosar. This is a non-issue.
This is a topic which is fun to discuss but impossible to solve. For example, Rodgers is also more talented that Ken O'Brien or Simms were, but he does seem a bit fragile compared to them, let alone Kelly, Stabler and Bradshaw, wouldn't you say?
Another HUGE difference is that WRs and TEs own the middle these days. QBs can send receivers there without worrying as much about them getting paralyzed or killed. Players such as Atwater, Lott, Tatum and many other safeties were extremely dangerous people. In a few years people will see these players on film and shudder in horror at the thought of such violence.
Again, Rodgers has all the talent in the world, but Chris Chandler was talented as well and he got destroyed in those days.