[Naruto] I may have figured out why Kishimoto had such a hard time writing Sakura (and no, it's not the "she's a girl" thing).
For starters, let's debunk the idea that Kishimoto is unable to write women; I'll do that by noting that, well, of course Kishimoto is unable to write women. He's not able to write men either, for that matter - don't make the mistake of thinking that Naruto and Sasuke are better written than Sakura just because they get to do more stuff than her.
Now let's try to be a bit more specific (and fair): I'm perfectly willing to grant that, say, Ino isn't in any way a great character - but come on, can you look me in the eyes and argue that Kiba and Shino are? I'm also perfectly willing to grant that Kakashi and Guy are decent enough characters, but I think anyone who is arguing in honesty should be able to agree that Tsunade and Chiyo - for example - are decent enough characters as well. Or: ok, Konan ain't super-deep or anything, but her villainy certainly has deeper motivations than people like Deidara ("Explosions. That's my thing."), Kakuzu ("Money is my religion.") or the guys from the Sound Four ("...uh, I guess we like that Orochimaru used us as guinea pigs? No, really, what's our backstory?").
My point is that, percentage-wise, I don't think the good/bad character ratio is much different between the two genders: it's just that there are more men than women in the series, which creates the illusion that Kishimoto is better at writing the former - but in actuality, he is an equal opportunity hack.
Having clarified that, I'll now get into the main topic of this rant; I believe the fundamental reason Kishi had such a hard time writing Sakura is simple: it's not that she's a girl, it's that she's (or was meant to be) a normal girl.
Here's the thing about Kishimoto: when you get down to it, the guy is a soap opera writer with a knack for writing fight scenes; the things he cares about the most are 1)the action and 2)that his characters get to emote the biggest, most extreme emotions possible.
This is why he felt right at home with characters like Naruto and Sasuke, whose sad backstories could be exploited from the manga's beginning to its end; this is why he lost interest in Neji once he got over his hatred of the Hyuga's main branch; this is why he never had much interest in characters like Kiba and Shino, who were decently adjusted from the start; and this is the source of Sakura's problems.
Kishimoto made her a normal girl with no tragic backstory to create a balance within Team 7, whose other two members were wallowing piles of angst; that was a sensible move in theory, but Kishi didn't account for the fact that he had neither the interest nor, frankly, the capacity to write a normal teenage girl - the concept just wasn't bombastic enough for his style. This is probably part of the reason behind Sakura's over-the-top reactions and the existence of Inner Sakura - Kishimoto needed her to do at least some BIG emoting, otherwise he would have had absolutely no clue what to do with her at all. It would have been even worse than what we actually got, believe it or not.
Following the Land of Waves Arc, Kishi figured out that there was a problem and made a first attempt at correcting it: Sakura gets her own rival (and since I know some of you will ask: yes, in the anime Ino appears early on, but in the manga this is where she gets introduced), a moderately sad backstory that fits with her being a normal girl (ending her friendship with Ino over Sasuke - and no, I'm not saying this was a good idea) and a hang-up to overcome (this is where she first says that she needs to catch up to Naruto and Sasuke).
Thanks to these additions, Kishimoto was able to give Sakura a couple things to do (and I do mean a couple: the fight against the Sound Ninjas in the Forest of Death and the 1-on-1 with Ino); the problem is that this stuff, while better than nothing, was still a far cry from the big, bombastic, super-emotional stuff Kishi likes to do - and the Chunin Exams introduced a lot of that: Hinata, Lee, Neji and Gaara became new sources of distraction for Kishimoto, and so his focus on Sakura was short-lived indeed.
But again, it's not like Kishimoto was blind to the problem; for a while, he could avoid facing it (since the Search for Tsunade Arc sidelined not only Sakura, but more or less the entire supporting cast) but, once it was time for Sasuke to leave the Village, it was also time for Kishi to decide what he was going to do about Sakura.
And decide he did: Sakura, exactly like Naruto, was going to have "save Sasuke from himself" as her key objective; Sasuke leaving the Village was now her tragic backstory, and his absence the source of the angst she had been sorely lacking before. His interest in Sakura revitalized by the fact that he could now write her the way he preferred to, Kishimoto proceeded to give her a major overhaul, turning her into Tsunade's pupil (thus putting her on the same level as Naruto/Jiraiya and Sasuke/Orochimaru) and then giving her what is objectively her best fight ever, the 2-on-1 against Sasori (in the process she was also given the honor of being, together with Chiyo, the first character to defeat an Akatsuki member).
But once again, a problem appeared on the horizon: you see, while Sakura now had Sasuke as her major source of angst, the fact is that he was also Naruto's major source of angst - and Kishimoto was never going to let Sakura be the one who redeems Sasuke in the end, any more than he was going to let Kiba become Hokage in Naruto's place. Therefore, Sakura found herself castrated on a narrative level, because her big storyline was also the big storyline of a more important character, which left her with nothing to do (plus, any emoting she could do about Sasuke could be done by Naruto as well, which made her redundant in the grand scheme of things).
Kishimoto, I think, figured this out when he reintroduced Sasuke in the Tenchi Bridge Arc; following that... yeah, he basically gave up on Sakura, and more or less put her on the same level as the not-completely-useless-but-not-very-useful-either Konoha 11; during the Summit Arc he gave her the infamous "fake confession" scene, which might have been his last-ditch attempt at revitalizing his interest in her by taking the soap opera stuff to the highest possible level - but his heart wasn't in it by that point, which is why that arc ends with Sakura realizing, and I quote: "I can't do anything. I can't say anything. All I can do... is trust them!"
She accepts, in other words, that she's ancillary to the series' main conflict, and I think this may be where Kishimoto accepted it as well - accepted that he had failed with her and that there was no longer anything he could do about it, that is. And so, in the War Arc, Sakura once again plays second fiddle to Naruto and Sasuke, and by this point there's no attempt (or barely any attempt) on Kishi's part to disguise the simple reality.
And this, I believe, is the true story of Sakura Haruno. Thoughts?