I totally accept the premise that there is a significant amount of vitriol directed against the paleo community around the internet.
The explanation for this, in my opinion, is simple: Because our good friends in the mainstream media command the people to mock the paleo diet. Period.
From the anti-paleo TED Talk to U.S. News & World Report ranking paleo as the worst possible diet every year, to the NY Times publishing anti-meat articles every week (which get posted religiously on my Facebook wall by fuglies)....the media hates us. (I suspect they hate paleo because they hate white gentiles and want us sickly and depopulated, but that's just a theory.)
What the media commands, the America public obeys (though with many exceptions). Whether the topic is 9/11, the murder at the Boston Marathon, racial demographics in violent crimes....if you express thoughts that diverge from the media's edicts, you're to be marginalized and subjected to hatred.
Unless and until a critical mass of people stops consuming the MSM, the hatred against paleo and other "alternative" communities will continue.