Is your opinion of unions based on personal knowledge/experience?  Upon what, exactly have you formulated this broad view? 

negotiations for contract renewal and the opening of a union shop in a location which previously had no union.  I've been in management & craft in both the public and the private sector.  In EVERY instance the very FIRST thing that was demanded by the union was dues checkoff ...... the requirement that the "company" collect union dues from member's paychecks and proide them to the union.  The union, understandably, had zero desire to have to collect dues from its membership.  Again, this was always the first demand by the union when negotiating .... not wages, not working conditions, not seniority, not benefits, not worker safety.  I found it rather telling.