As long as people are convinced "SEC is overrated because ESPN", there will be no reasoning that will sway them. I can point to unbiased systems till I'm blue in the face--systems that do not watch ESPN and have no understanding of conference affiliation or even team name--no one will bother.
These systems are made and influenced by people, who are influenced a great deal by ESPN.
It's not possible to make unbiased systems in a vaccuum that doesn't have ESPN influence.
Yes, it is. Unbiased means the computer does not know anything about the teams or conferences. Just scores. Unless the scores were somehow significantly different between conferences on a regular basis (in other words, if a program could look at 100 SEC scores and 100 Big 12 scores with no teams and be able to tell based only on the numbers which conference was which), there is no way to intentionally skew the system towards the creator's favorite team or conference.
A lot of these creators are pretty brilliant guys and many of them have published papers on their methodology. They would tell you it would be extremely difficult or perhaps impossible to program an unbiased rating system to favor any conference, even if they
wanted to. Some of them are very accessible via email or Twitter: Kenneth Massey, Wes Colley and perhaps Peter Wolfe (who also was friends with the late David Rothman and probably knows most of the ins and outs of his system). You could certainly debate the point with them if you like.
Not to mention all of the top systems were formulated years and years before ESPN created the SEC Network.