They're trying to make the whole movement look dumb by proxy, or that anyone who joined the movement is dumb because they're following a dumb guy. The public PR angle is that only a dumb stupid babbling person would deny the goodness that Amazon does for its employees and try to organize a walkout.
I think it's interesting the contrast with the SVP who said he let his emotions got the better of him. If the union guy says something not-smart, he's dumb and the whole movement is dumb. If the SVP says something not-smart, he was just trying to protect the workers.
Before liberals downvote me. Conservative media does this too. In fact, journalism these days regardless of political views is riddled with making someone look bad to score cheap points. One of the most toxic more recent developments is taking particularly unflattering still images from high definition video to present someone as dumb, stupid, angry or any of the myriad emotions one might present in the course of existing while filmed.
Making your opponent look bad is sadly par for the course pretty much everywhere these days from politics to corporate PR to social media debates on facebook and twitter. Heck, you see it here on HN too these days. Certainly far more than in the past.