This article by Elliott Maggin is from the April 1984 issue of On Cable magazine.
When the article shifts gears and starts to talk about Superman III in particular instead of the Super-Mythos in general, I begain wondering if this part of the article wasn't writtn by Maggin, but by a magazine staffer, until I came across the line at the bottom of page 20 (the second page of this scan) about right and wrong in the universe.
Maggin is only one of thousands (millions?) of us whose lives have been enriched by knowing "uncle" Superman. After all, it's hard to beat Truth, Justice, and the American Way.
PS as to the riddle posed by the title of this post -- notice how Maggin is credited on the first page of the article. They didn't replace the period after the "S" with an exclamation point, only a period. "We all know" that his official tag is "Elliott S! Maggin." If you'll note, I gave you a clue by putting an exclamation point at the end of the post title!