I don't really understand the purpose of the unionization effort, beyond the facade of just wanting to in some way "fit in" with a social movement.
It's pretty naive to think unionization is just a social fad. It's a path towards job security, safety, good pay, and control over the direction of your own labor. Trendiness is pretty low on the totem pole.
The alternative is complete control by the employer. Sure, a union, as an institution with power, can likely limit some of your independence, but an employer can limit all of it.
Sanders is in the 1% as well.
Just because someone belongs to a group, doesn't make their criticism of the unjust advantages of that group invalid. Similarly, a white person arguing for civil rights is not a hypocrite either.