Without union protection (is it down to 13% of the US working class overall in a union now?) walking off the job will get one fired or at least reprimanded. "At will" contracts mean non-unionized workers will and can get the axe instantly.
Will TONC with Brian Becker fight on behalf of fired workers who walk out for their unemployment benefits (usually half of net wage paycheck, oh boy!) Buy lentils to feed your family on that while you look for another job.
Advocating this tactic w/o having any means or intention to help support those who do walk out is ultra-left irresponsibilism. High school students in LAUSD who walked out on Nov. 2nd for the World Can't Wait protests? Expelled.