I realize this is an old topic, but I'm new to this site, and I thought I'd offer my perspective as one of these graduate instructors.
First, I'd like to offer a little bit about our qualifications - hopefully this doesn't come off as self-back-patting.
In the program I'm in, grad students either TA or grade for the first 3 years. As a TA the typical format is a big lecture (around 200 students) twice a week by the professor and then the gradstudent TA leads discussion on Friday and does all the grading. Usually a TA will have 2 sections of 40 students. Graders don't lead a discussion, but they have more to grade (usually more than 80 students and the papers are typically longer). This is all done under the guidance of a professor.
In our 4th and 5th year, we can teach our own classes (typically 40 students per class). To do this, we have to be in the dissertation writing stage of the program. Students in this stage are done with coursework and the only thing separating them from a PhD is the dissertation. This also means we have our master's degree, which is typically earned after the 2nd year, and have passed all qualifying exams, which are done at the end of the 3rd year. And all of this work has been done at UIUC, which is a top 50 grad school in our field.
All that being said, are we as knowledgeable as the professors? In some areas, we certainly are not, but in material at the 100 level? There's really not much difference. By the time we have our own classes, we've been TAs for 3 years, so not only have we seen the professors teach this material, we've seen which parts of it students struggle with and can adjust our own classes accordingly.
Do we lack in experience? Certainly, compared to professors who also taught through grad school, we lack some experience, but having a young teacher isn't always a negative. Our material is always fresh. There's simply no way we could be using 10 year old slides. Our books, too, should be current. It's not like we're just using the same textbook that we've always used. At least for the first year we have to seriously consider what books to get, look through samples, etc.
Also, high course evaluations are very important to us. If for no other reason, the job market is not great and good course evaluations can help separate us from others on the market and could make the difference between finding a job and not, especially at colleges that emphasize teaching. (this also applies to non-tenured faculty). That means we genuinely care that our students are not just learning but also enjoying the class. (I don't mean to imply that tenured faculty don't care, but with us, our jobs are on the line, so we care that much more)
Could you get the same education (at the 100 level) at Parkland or EIU? Possibly, but I'm not convinced yet. I know that some of our grad students occasionally teach at Parkland as well. What I don't know is whether or not they teach all the same material. Courses are, to some extent, tailored to the students.
Looking at EIU, a lot of the professors I see there (in my field) are from schools that are ranked lower than UIUC (or not ranked at all, like SIU). I'm not saying they're worse teachers because of that - especially at the 100 level. What I am saying is that a class being taught by a grad student isn't necessarily worse than one taught by a professor. You have to look at where the teacher is coming from and what they've done.
One area EIU does have an advantage in is class size, which is sadly something I have no control over. However, if students at UIUC would like more one on one time with their teachers, I strong encourage them to attend office hours. If one or two students a week show up, those students can basically have an hour of one on one tutoring. If more students than that show up (which in my experience is rare), it's often the case that they have the same questions. Then it's no longer one on one tutoring, but it's more like a class with 5 students in it. Either way, office hours are a good way to get some of the smaller class size benefits at a larger school. (sorry for the plug, but it kills me to see students struggling and not come in for help).
I'm not sure this will convince anyone that taking a 100-level class from a grad student is just as good as taking one from a professor, but hopefully I've given you some reason to think that we really are qualified to teach these classes and that there's even some advantages (fresh material, etc.).
As for the strike specifically - the only real issue left at the time of the strike was tuition wavers. In my field (and I think in the humanities generally), any respectable grad program will offer tuition-waver generating appointments. The one piece of advice about applying to grad school that I got from all of my undergrad professors was: don't go somewhere if they don't offer you a tuition-waver. Professors in the humanities just don't make enough to justify 5-6 more years of debt (on top of whatever undergrad debt one had). I'm not sure why the university was hesitant to put tuition wavers in writing, but I was certain it wouldn't take them long to do so.
