There is no evidence that the Selection Committee is biased against the SEC. In fact, quite the opposite:
http://uselectionatlas.org/FORUM/GAL...3_10_53_44.png
Only once in the past 11 years has the SEC not had the most bids, or tied for the most, to the NCAA Tournament.
You can certainly say there's a "bias" toward letting Western or especially Northern teams getting to host with weaker resumes, but that is the NCAA's attempt to expand the sport, and also partially due to the idea that those teams don't have the financial opportunities to play tougher schedules, artificially weakening their RPIs. Whether or not that's true, it's not just the SEC that it affects.
There is absolutely no need for an SEC persecution complex in baseball.