I don't think that it is fair to call these systems, including the speakers in the OP in particular, junk. It's a matter of perspective.
Small table-top systems like the one pictured were commonly sold in department stores and they served a purpose. They were sold at a price point that made them inexpensive enough so that were affordable by almost anyone. And that enabled families to enjoy music that otherwise may have been out of reach. All things considered, many of these systems didn't sound too bad. I don't think that anyone that sold them or any of the polyester leisure suit wearin' dudes that bought them believed that they were equal to the kinds of equipment that was being sold in specialty high fidelity stores at the time. I am sure that in many cases these small entry level table-top systems were a stepping stone for those that later wanted true high fidelity equipment and were then willing and able to afford it.
So, back to the question in the OP, as long as you are not attempting to compare them to true high fidelity speakers connected to much more expensive equipment, and especially considering what the speakers cost which was not very much, they are OK for background music or general non-critical listening. And yet still today there is a nationally and internationally known brand of speakers that hang their hat on much the same technology and marketing methods as those Zenith Circle-of-Sound speakers to quite successfully sell a lot of their products. And again, to be fair, in the right environment and with the right set of circumstances, they too can sound not so bad. All things considered, that is.