Kickstarter is a software firm based in New York. There's no shortage of firms hiring in New York. Kickstarter employees who are unhappy would be able to easily get jobs elsewhere.
However, observe that their goal is not to tackle abusive working practices but apparently to take over the firm and impose a "social justice" agenda on it:
enrich Kickstarter’s charter commitments to creativity, equity, and a positive impact on society
promote our collective values: inclusion and solidarity, transparency and accountability; a seat at the table,”
"equity" means equal outcomes e.g. 50% of all jobs being reserved for certain genders, races, etc. "Inclusion" is a codeword for the same thing.
Obviously the goal of forcibly converting Kickstarter into using identity politics based management isn't something they can achieve by just going to work elsewhere, as would be the case if they were being mistreated, because Kickstarter would just hire replacement employees.