In this instance, I am not sure it is the union. Sure there are drawbacks to them but, overall, they are part of the capitalistic model. I have no problem with private unions since they are just as responsible for the viability of the company as management. If either screws up, it is bankruptcy.
Here I dont think it is the unions as much as a shift in the way the world operates with entertainment. The late night television lineup simply isnt important to people.