More from the article...

... The USPTO's Trademark Trial and Appeal Board ruled for S.J. Richold's Superbabies Ltd, opens new tab after Disney's (DIS.N), opens new tab Marvel and Warner Bros' (WBD.O), opens new tab DC did not file an answer to Superbabies' request to invalidate the marks.

Spokespeople and attorneys for Marvel and DC did not immediately respond to requests for comment. Superbabies attorney Adam Adler of Reichman Jorgensen Lehman & Feldberg said in a statement that the ruling was "not just a win for our client but a victory for creativity and innovation."

"By establishing SUPER HEROES' place in the public domain, we safeguard it as a symbol of heroism available to all storytellers," Adler said.

Rivals Marvel and DC jointly own four federal trademarks covering the terms "Super Hero" and "Super Heroes," the oldest of which dates back to 1967. ...

OK, I'll admit that I did not read the legal stuff behind this decision, but based upon the article, it seems to me that DC/Marvel may have gotten a bit too aggressive in claiming trademark infringement with any character descriptions starting with the word "super" and, as a result lost their "Super Hero" trademark(s).

fwiw, I am not a lawyer...