It's difficult, because it's not all that widespread of an issue...like I said, I've only noticed it in a few shows. But RWBY is the most obvious one. All the characters are pathetically written at this point, but the male characters are consistently much more so. I don't wanna get into it; I could write whole essays...^^;
The thing is, they're actually NOT better developed...I mean, if you consider 'development' to be more than just piling on sad backstories to force an emotional response from the audience.
It's more about presentation...they are presented as victims, as people who just need to be saved, as people who can change their minds and motivations (often at the drop of a hat, but still). And their male counterparts just...aren't.
As some others have mentioned, I think this is probably a more common issue in anime, where misery porn for female antagonists AND scenery-equivalent roles for male characters (if you can't be sexualized and objectified, you're kinda just in the way) are far more prevalent.
Of course, a lot of anime with that level of pandering more or less eliminates males from the relevant cast entirely, so you end up with scarcity again. ^^;
I think what I'm trying to say that it's a niche issue...noticeable, but niche. You'll really only find it in shows where the writers DO want to pander to viewers who just want to look at cute girls, but delude themselves into thinking they don't, so they half-ass it. They make an effort to include male characters, and immediately after they stop trying with them.
