Not in the least. It is the living demonstration of the right of free association and collective bargaining. Don't blame unions for the unbalanced legal situation created by government legislation (NLRA). Those doing labor or service have as much right to form a body to negotiate working conditions as any corporation.

The Communists (and Nazis) were so opposed to the independence of unions that they mandated that they should all be under government control.

If an individual worker is being treated unjustly by the employer (violation of contract terms), there is no one to defend him but a union.