Some disturbing correspondence has emerged between Jerry Siegel, co-creator of Superman, and his publisher Detective Comics (DC), including this little bit of criticism:

Another alleged problem with Shuster's artwork is that it made Superman look gay--or in the period slang of Ellsworth's January 22, 1940 letter, "lah-de-dah" with a "nice fat bottom"--

Also problematic is Lois Lane being too sexy, and in general the quality of co-creator Joe Shuster's artwork.