Though there was more male dialogue than female on the show, the men were constantly portrayed as stupid, weak, aggressive, drunk, selfish, not responsible...
Everyone is flawed on that show, even ol' Painty Can Ned.
Most of the male (and female) characters are ridiculous, because the show is fundamentally about ridiculous people. But that's not the only kind of character they have.
Smithers in the archetypical yes-man.
Dr. Hibbert isn't so much a stereotype as much as a parody of Dr Huxtable.
I'd say, totally superior, this was in 2000:
https://en.wikipedia.org/wiki/Bart_to_the_Future
"Lisa has become the (first female) President of the United States and tries to get the country out of financial trouble."
And I don't consider that "morality" was the major aspect of Lisa's superiority.
When the plot is about Home and Bart, the other two play counterpoint. But the opposite is true. Homer just ends up getting the main role so often that we assume that to be the default state of the universe.
Which is just how it goes. It's unfortunate but you can't strike a 50/50 balance. Even for side-characters written as female in the script, they're going to become male during production because you don't have female voice actresses who can make a "different" voice; it would just sound like Lisa or Marge. Really only Bart's voice actress can do it (she does Nelson, too, who sounds very different).
They're not for everyone, and the voices are still mechanical, but I've become a huge fan of English Vocaloid, especially Gumi.
Take Tara Strong. Sure, lots of her voices sound a little similar (you might hear Timmy Turner, then hear the girl in Batman, and think "oh yeah, they do sound similar" once you knew they were the same voice). But she can definitely "transform" her voice.
The male voice actors on The Simpsons have incredibly transformative voices, which I think comes from lots of practice in the industry. The first time I saw a chart of all the voices for each character they play, I couldn't believe it. After paying very VERY close attention, I can kind of hear Mr. Burns in Moe, but just barely.
Edit: he also did a made-for-YouTube miniseries wherein he re-enacts actual transcripts from the Nixon White House tapes: https://www.youtube.com/watch?v=f9HtoWea72A
https://en.wikipedia.org/wiki/List_of_The_Simpsons_cast_memb...
In no way does it look like the cast is "mostly male", or that the women are cast into single roles.
The Simpson's were kind of famous for Bart being voiced by a woman, meaning the Simpson family has 3:1 Female:Male voice actor ratio.