Why are all the workers not on strike?

They are scared of retaliation by UNICCO. The National Labor Relations Board has already charged UNICCO officials with unlawful spying, interrogations, threats of reprisals, and various other unlawful actions against the union supporters. One of the union organizers whom UNICCO has not fired yet was asked by a member of the audience at a recent event why some of her colleagues had not walked off the job. Her response was, "They are so afraid." With UNICCO's record, they have good reason to be.

They are also scared of even greater consequences than job loss. Three of our faculty colleagues – Elizabeth Aranda (Sociology), Elena Sabogal (Latin American Studies), and Sallie Hughes (Communication) – had this to say in response to a question from another faculty member about the strength of strike support:

We have been researching the immigrant/Latino communities here for a couple of years now. In the course of our research, we have spoken to UNICCO workers on campus. One of the things we have learned is that many are part of a vulnerable
population—more than earning poverty wages, these workers share an immigrant
background that places them at an additional level of disadvantage. We speculate
that some of them cannot afford to engage in civil disobedience because they
know this could jeopardize their immigrant status. It's not just about losing
their jobs or missed wages—they could put in danger the right to be in this
country. One thing we have consistently heard in our interviews is that life as
an immigrant has become harder to endure since 9/11 due to increasing fears of
deportation in spite of being in the country legally. So, they lay low—something
that is incompatible with a public demonstration. We feel this makes their fight
even more courageous. In speaking to some of the workers in the past week, they
have expressed to us how much they appreciate that students and faculty are
fighting their fight. Even though some who we have spoken to do not plan to
picket, rather than interpret this as a sign of ambivalence or non-support, in
our view, it is part of their strategies for survival that involve remaining
"invisible." The legal community could probably speak more on this issue that we
can, but many immigrants feel that even if they are here legally, they are
subject to deportation if they are arrested. This underscores their
vulnerabilities as a population marginalized by multiple structures of
inequality, something we should keep in mind as the strike unfolds.