Did you read the minutes or are you assuming these are just dumb, racist, country-bumpkins? They literally address exactly this point.
From the minutes (regarding removing this book):
> My bigger concern is that this is probably the tip of the iceberg of what is out there.
1) I ask you to refrain from personal attacks if you want me to continue to engage.
2) I feel no moral compunction to read a twenty page supporting document to make a one-line comment about not trusting people's claims uncritically.
3) Having now read that document, my opinion hasn't changed. One person tries a couple of times to address the bigger picture about what problematic books are in the curriculum. In both cases he is almost immediately shut down by the rest of the committee who want to discuss this particular book.
I don't expect you or anyone else on HN to read the supporting text, but I do expect some level of empathy, assumption of good faith, and seeing past sensationalism. Instead I see a lot of cargo culting, demonizing, and propagation of incorrect information.
Having listened to an agonizing number of school board meetings, and having family that is involved in school administration, there are reasons to not let a topic expand past the original scope for the sake of the board, the parents, and everyone else involved.