I think one problem as well is that the Greek Pantheon has had little effects on the greater DC Universe. As I stated above this is much the case with things involving Wonder Woman, but I find it particularly troubling with the Pantheon. The topic title of this discussion is why WW's villains suck. I think almost anyone would state the God of War, Ares, as villains go does not suck. Now the interpretations may or maynot suck, and the execution of such a character may suck, but I don't think many on paper would say, "Yeah, the God of War, lame."
Over at Marvel, when they unleashed Loki on the greater Marvel Universe, it required the formation of the Avengers to match him, and his schemes. The number of times I've seen Ares in conflict with Superman or Green Lantern is nonexistant, though I'm sure it happens, it's nowhere near as prevalent as it should be. The comic series Blackest Night dealt with characters being Black Lanterns that are brought back from the dead. Where was Hades during all of this? He is God of the Underworld. In the various Crisis storylines, they are at best in the background. I can't remember seeing any of the Greek Pantheon appear in Justice League, ever.
As I said in the above post, Wonder woman and her stories are often kept out there on an island all to itself. As such, people say her characters are lame, even though many of the villains they love Wonder Woman would make short work of. The ignorance though of writers is comical at best and horrid in worst. Cheetah is constantly undervalued, Circe is gotten wrong in her only cartoon appearance, Ares and Hades are seemingly interchangable at times even though they are completely different characters.
Many fans of Wonder Woman came from the Lynda Carter TV Show. As far as I know, the only two villains to appear in both the show and comics are Paula Von Gunther (A villlain in the golden age, who rehabilitated herself, and post crisis was seen rarely), and Fausta (who has appeared in a very few amount of issues ever). That's it. No Cheetah, Ares/Mars, Hercules, Dr Poison, Dr Psycho, Giganta, Dr Cyber, no one. The thing that made Joker, Penguin, Riddler and Catwoman household names wasn't the comic books. It was the TV show. let alone is it bad enough the TV show did not use many of the comic villains, the comics in turn never explored any of the TV villains.
I think one thing though that would have to be explored is in what ways do individuals feel the villains stink at. Is it popularity, power, schemes, ability to interact with Diana, etc that is the gage at which we explore various villains. I think for example, in terms of popularity, using a villain like Ares, and comparing him to Joker, Ares has looked massively different depending upon who was the writer and artist of the book, whereas Joker often has the green hair, the crazy smile, purple clothes, etc. If you had the choice to put Joker or Ares on a T-shirt, who would it be? It's Joker, but not because of his storylines or because of his power, but in all truth, it's because he's recognizable. Joker is one of the most popular characters in the history of comics, whereas Ares is not even remotely a household name in terms of the comic character. I think when DC ditched the Perez redesign of Ares, it was actually a major step back, as apposed to a step forward. At Marvel, Loki is recognizable, if I showed you a picture of Mars from the early WW comics, then the late Vol 1 issues, and then the Perez version, the Rucka version, and now the Azz version, they don't even look like the same character.