Yeah, and in doing so keeping sh*tty employees employed. If management can't remove these employees and replace them with the best available because the Union won't let them, how is that management's fault? Clearly the Unions are protecting sh*tty employees.
Their mission of the is to serve the best interests of their members -- that part is good. The problem is that many unions interpret that mandate to mean "protect members at any cost, including ones that are really bad apples". If they all understood that getting rid of the bad apples is in fact beneficial to both the employer AND the union members, they would serve a much more useful function and be more accepted as beneficial in general. By shielding crappy employees from consequences, unions have significantly hurt their own credibility and image.