It says that they didn't use him. Odds are, in a show that was clearly geared toward presenting a diverse group of superheroes, that they thought he was too similar to Superman, much like Captain Marvel, who I believe didn't show up in a SUPER FRIENDS/SUPER POWERS show for some time, and even then only mainly in merchandising and the SUPER POWERS toy line.
And yes, to a point, the writers of SUPER FRIENDS were terrible, and they obviously didn't care about the source material, at least at first.
Plot lines for the first incarnation of the Super Friends did not involve any of the familiar DC Comics super-villains. They focused on the far-fetched schemes of mad scientists and aliens, who were invariably revealed as being well-intentioned, and simply pursuing their goals through unlawful or disreputable means. Typically, at the end of each story, all that is needed is a peaceful and reasonable discussion to convince the antagonists to adopt more reasonable methods.[7]
SUPER FRIENDS was about well known superheroes interacting with kids and their pet dog/monkey/whatever they had, and a certain amount of diversity and lesson learning. That's why Superman, Batman, Robin, Wonder Woman and Aquaman, well known DC icons at the time, are present, and almost every other major character is a guest star, like The Flash, or has some diversity element added to them. At one point, Green Lantern had a little asian sidekick who rode him through space.