I think once they got to the point of forming an actual union (which, at Google, has a historical risk to job security) the "slactivism" potshots became inarguably unwarranted.
Agreed - I think skepticism is usually warranted, and there are unions that are very active in doing "union things" in America that do more harm than good to the working class. I just took issue with the "slactivism" complaint specifically, because by starting the union the employees involved put themselves at risk of being fired. To me, continuing to call that slactivism is moving the goalposts to an unfair degree.