[FarmBoy]

I don't think so. 

You win the conference with the best players. Remember, these are voted on by the coaches.  And they have nothing to gain by coalescing around only players from the team that won the conference.

You win the conference with the best players, coaches, schedule (home vs away split), and the ball bouncing your way when it matters. You can't pretend that (a) only player skill/talent matters and (b) coaches are immune from being biased towards players from teams that win rather than seeking out the best talent. 

On average, I am sure the list does a good job, but on average, I suspect that on the margin players will be promoted or demoted based on team performance as well.

The only way I can think to check this would be to look at a list of players who made all conference teams vs those who didn't and compare it to the NFL careers for those players. I am sure we'll find players who didn't make the all conference teams who went on to have strong NFL careers.

[FarmBoy]

I don't think so. 

You win the conference with the best players. Remember, these are voted on by the coaches.  And they have nothing to gain by coalescing around only players from the team that won the conference.

You win the conference with the best players, coaches, schedule (home vs away split), and the ball bouncing your way when it matters. You can't pretend that (a) only player skill/talent matters and (b) coaches are immune from being biased towards players from teams that win rather than seeking out the best talent. 

On average, I am sure the list does a good job, but on average, I suspect that on the margin players will be promoted or demoted based on team performance as well.

The only way I can think to check this would be to look at a list of players who made all conference teams vs those who didn't and compare it to the NFL careers for those players. I am sure we'll find players who didn't make the all conference teams who went on to have strong NFL careers.