Seems like dark-themed shows are really all the rage now, and this one is definitely in that genre. Plus, I think EVERYONE, adult or youngster, knows what it's like to be bullied and teased and feel hopeless to do anything about it. The audience can live vicariously through these two characters, who, while flawed, have a black-and-white sense of right and wrong. This is meant to be a limited series, and I liked placing it in the '70s, early '80s because I went to junior high and high school during this time and really liked the period, just not some of the unwanted issues... like being bullied and teased.
It also deals with some taboo issues like incest and open marriages and how these things would have to be kept secret for fear of losing one's job, in the case of Principal Wexler. With Rubber and Glue, we're teased for a while as to what their relationship really is, but the implication is that initially, they may be related, which could explain why they move from foster home to foster home once their taboo relationship is discovered.