You might be right. Many famous OTL super heroes (Batman, Superman...) has invented during or just before WW2. And these were usually promoting fighting will of Americans. Leastly super heroes are bit different from OTL super heroes. Perhaps them has some weakness and bad guys not be absolute evil.
This. I'd imagine that they'd be a lot more influenced by pulp fiction as well...and with no attempts to limit the amount of horror and sex, I'd imagine super heroes would only be one category of the broad medium of comic books with mass appeal.