Well, with respect to adjuncts, it's not wholly accurate. It's a complicated subject that varies from place to place; so, I'll be speaking specifically about experiences at my own large state institution, but many of these points hold generally as well.

First and foremost, yes, adjuncts have it terrible. They are absolutely being exploited by administration to lower costs. Unions are one solution, another (which I prefer) is a push away from adjunct contracts in general - in other words, rather than attempting to make things slightly better for adjuncts, working towards different types of contracts (teaching professors, etc.). Both projects are largely necessary and depending on where one is one may be more feasible than another.

However, to suggest that adjuncts do "the same work" as a professor is misleading. At most places, adjuncts do not have service loads nor research expectations. Those make up 66% or more of a tenure professors job. So, to say that someone doing 1/3rd the job (just the classroom part) for 1/8th the pay is doing "the same work" is inaccurate. That person is being exploited and treated horribly, but they are not doing the same job as a tenured professor.

Of course, the administration does love to try to creep service and research onto adjuncts, but that's a different matter. This is ultimately about labor.