(1) DC Comics was launched principally by two men, Harry Donenfeld and Jack Liebowitz, who had a well-documented history in producing sexy pulps ("the kind men like," as some old slogan put it). Getting into kids' comics was their way of becoming respectable, and throughout the Golden Age the company usually advocated a squeaky-clean approach to juvenile pulp entertainment. Aside from the Marston WONDER WOMAN, most DC features allowed only for minimal sex appeal, though one can see artists "letting themselves go" to some extent with certain characters-- Catwoman in BATMAN, Hawkgirl in HAWKMAN, and a handful of others. Yet Frederic Wertham persuaded many middle-Americans that all comics-- with DC books getting many of the citations-- were crammed with salaciousness.
(2) In contrast to comics, which retained a bad reputation even after the institution of the Comics Code, television quickly became known as a "safe harbor" for middle America. That's not to say that various individual programs didn't get criticized for sexy stuff-- though I've the impression that violence was the more frequent target-- but the major TV stations successfully "sold" themselves as purveyors of respectable entertainment. Yet in 1966, the BATMAN teleseries brought about a sea-change in DC's BATMAN feature-- and it did so by playing up the very salacious qualities that were almost invisible at DC Comics during its Golden Age.
For its first twenty-something years, the Catwoman was pretty much the only "femme fatale" in the Batman features that ran in BATMAN, DETECTIVE COMICS, and WORLD'S FINEST. There were a smattering of one-shot molls or "damsels in distress," and a handful of recurring leading ladies, of whom 1948's Vicki Vale remains the most famous. Given what I've seen of DC's editorial tendencies during the Golden Age, I hypothesize that the editors only kept Catwoman as a recurring villainess (1) because she had appeared in the first few years of the Batman feature, before the editorial routines became set in stone, and (2) because the editors thought she was popular with readers, probably as a result of enthusiastic fans writing the DC offices (though I don't think any Golden Age DC Comics maintained a letters page). Only with the advent of the Silver Age-- which I date as beginning in 1954, with the Comics Code's advent-- did the Batman feature accumulate a few more crucial female presences in Batwoman and Bat-Girl. It's been alleged-- though never decisively proven-- that both characters were introduced to defuse Wertham's accusations that the Batman feature presented a "homosexual wish dream." In any case, both characters disappeared in 1963, with the feature was revamped in tune with Julie Schwartz's "New Look." In addition, Catwoman made no appearances in any DC comic from 1954 to 1965, finally showing up in a 1966 issue of LOIS LANE.
However, even though the BATMAN comic wasn't overflowing with femininity when William Dozier decided to launch his Bat-series, Dozier clearly meant to pump up the pulchritude from the first episode, with Jill St. John getting special billing as the Riddler's gang-moll. There's also a scene in which a gaggle of young girls are seen screeching over their sighting of Robin, as if he were a superheroic version of a Beatle. [Correction: this scene was in the third episode.] Later in the series' first season, Catwoman, exiled from kids' comics by conservative DC, made her triumphant return in a medium aimed firmly at a general, middle-class audience, and arguably became as popular with the show's fans as the main heroes. This, according to interviews with DC artist/editor Carmine Infantino, led DC to create two new female figures for the Bat-mythos, for possible use on the teleseries: Poison Ivy and the 1967 Batgirl-- though only one of the two made an appearance on the BATMAN show.
I lived through that period, and while I imagine some Wertham-like figures may have critiqued the BATMAN teleseries, I don't remember anyone being torqued at the series' mild salaciousness. But the 1960s was a very different decade from the 1950s. It's possible that Frederic Wertham's screed may have owed its success largely to a "perfect storm" of contingent factors that only came together in the fifties-- the government investigations of organized crime, postwar malaise, fear of rising juvenile delinquency.
A third irony: though Wertham would never have credited it, he and DC's editors were close to being on the same page. The good doctor looked askance at almost every sexy and/or violent image he saw in comics, all a-twitter that it might cause some poor child to lose his innocence. DC's publishers, in contrast, had made their early fortunes in part from selling sex to whoever could pay for it-- in theory, usually older customers-- and then decided, once they struck juvenile-pulp gold, that they would play it safe for the majority of the 1940s and 1950s. WONDER WOMAN was one of the few features where they gave its creator some leeway in the depiction of sexuality, possibly because their contract with Marston gave him some limited control of the franchise: other Golden Age female-centric features, such as BLACK CANARY, LIBERTY BELLE and MERRY, GIRL OF A 1000 GIMMICKS, aren't much sexier than ROBOTMAN or THE STAR-SPANGLED KID.
A fourth irony: the Comics Code effectively exiled the genres that had garnered the most public acrimony: i.e., horror and crime, which tended to surpass many though not all adventure-related genres-- superheroes, westerns-- in terms of sexy and visceral imagery. But the Comics Code apparently had a stultifying effect on comics-sales: according to Amy Nyberg's SEAL OF APPROVAL, DC Comics returned to a heavy emphasis on superheroes specifically because none of their other genres were selling very impressively. Yet though the Batman franchise remained fairly conservative in its use of sex-appeal-- as was generally the case with the other "big two," Superman and Wonder Woman-- one can see some loosening-up in the newer features.
For instance, here's a shot of Dream Girl from ADVENTURE COMICS #317 (Feb 1964), doing a "Marilyn Monroe" turn on superhero sexiness:
A year or so prior to the LEGION comic, DC debuted the Metal Men in SHOWCASE #37, and in the succeeding series creators Kanigher, Andru and Esposito rarely if ever failed to emphasize the romantic travails of the Platinum robot who plays Galatea to her Pygmalion-creator.
So some liberalization was bound to take place, if only for purely economic motives. But as far as transforming the BATMAN series so that it would eventually spawn a number of "Bat-babe" features-- three different Batgirls, a new Batwoman, a couple of Huntresses and a many-times-revised Catwoman-- the credit would seem to belong to William Dozier more than to Carmine Infantino and Julie Schwartz, much less those little old sex-mag makers, Donenfeld and Liebowitz.