What she means:
Kiba Inuzuka was one of the most thrown aside characters in the Naruto franchise. He was made to be the leader of Team 8 from the start of the Chunnin exams and has a very strong personality which sets him up nicely to be used effectively against the other strong characters, and thus developed fully to even him out more. He would also be a great gateway into using shinobi using animals for combat as well as clans that specialize in using animals as partners in combat but we barely get to see anything about him even when he is shown in combat against Sakon and Ukon, which is probably the most exposure we see of him in the entire manga. What I find to be even more infuriating is that he is arguably a more intense version of Naruto. He is a Naruto-clone. They both are obnoxious and stubborn, as well as irrational but determined to gain respect and attention from others. They both have a short-temper and insist on being the leader of their teams. What's even worse is that they both dream of being Hokage, which is obviously not going to be fulfilled as it is Naruto's dream and he is the titular character of the entire story. They both even have animal-like qualities, Kiba's fangs and Naruto's whiskers, and can transform to be more like the animal they represent. Kishimoto seemed only to make Kiba not even as a foil or a rival to Naruto, as those are Sasuke's roles in the manga, but if anything as the "rival" for the NaruHina shipping by creating a very similar character to Naruto but who is closer to Hinata from the beginning. Though this attempt is vain at best because it did not pick up as feverently as NaruHina did, because of Kiba's very small exposure throughout the manga, and when we do see Kiba he is in a stalemate of development because he is a Naruto-clone and has Naruto's base personality. Kishimoto seems to not have had an idea of how to develop Kiba other than like he developed Naruto, so he ignored Kiba's development entirely. This is even more exemplified overall in Akamaru's story where he notes that Kiba wants to become Hokage and Akamaru has a strong belief that Kiba will become it, though Naruto is already Hokage. Though Akamaru's view is biased and limited as he is a dog, it does reflect Kiba's own view as Akamaru is the one who is closest to Kiba. Also, Kiba is constantly set up to be below Naruto, maybe not on purpose, but definitely to stagnate his character development further. He is told to be one of the last of his peers to end up with someone, and by the time that Naruto Gaiden takes place, he does not seem to have a child yet as opposed to almost all of the rest of his peers, which is limiting the further gateways to animal-based shinobi tactics that the next generation seems to be lacking of, as Shino also seems to not have a child either. It's so strange to me that this happened, as Kiba's an inherently good-looking person, is a strong shinobi, and has a very outgoing personality, so I would think that he would garner some romantic attention from others sooner than it is shown. Yes, he's obnoxious but so is Naruto and as I said they're very similar people. Maybe he's an example of what Naruto could have been if he took his life in a different path? Is he what would have happened if Naruto didn't actively chase his dream, as well as Sasuke, and which such determination to become stronger? Kiba didn't have a driving force such as that to get stronger and develop his character, but Hinata developed further throughout the manga and I think Kiba would have gotten chances as well to develop even with the lack of earth-shaking developments, he should have grown as a person. Especially since he was around Konoha more during the timeskip, he should have more established relationships with others as well, but it does seem like Kiba doesn't even have that much of a friendship with Hinata anymore either, now that she's with Naruto. As in Akamaru's Story, he does see them out in the park but he does not approach her to say hello. I'm just so confused as to why Kishimoto would create this character that had a lot of potential but instead he just basically threw the character out. Other than Shino, I believe that Kiba is one of the most neglected characters in the whole series. At least Shino had his own distinct personality and is inherently a very quiet person, though that doesn't excuse his neglect either it would make more sense why we hadn't heard about him as much. But as Kiba is one of the more outgoing shinobi of his peer group, it just strikes me as odd that he wasn't exposed or developed as much as he could've been, as when we see him as an adult he still seems to act very much like he did from the beginning, didn't seem to garner a lot of attention from others, and in general just seems to be at a stagnant place in the manga's present timeline, which is a very big waste in my own opinion.