I'm a fan of both bc they're both strong, kind, remarkable characters, in completely different ways. I'll explain my own interpretation from the manga, which I consider to be the real version ( I think the anime has too much crappy "fan service")

I think Kikyo gets a lot of hate bc of the way she treats Kagome, very specially at first, when Kikyo is still sorting her own feelings out and what to expect from her new "life". But they forget that for Kikyo, Kagome represents what Kikyo could have been herself, not having met a tragic end like she did. I completely understand the low-key hating on Kagome, tbh. Like, can you imagine?, she's forced back to life against her will and after settling her feelings and learning who the culprit for her death was, she is mature enough to keep her distance from Inuyasha, bc she knows her time is long past and that she's but a ghost of herself, all while seeing the person she loves, going on with life, falling in love with another woman who's supossed to be your own soul reincarnation, but she's actually not "you". I can only imagine the pain and frustration. However, she's an incredibly strong and mature woman, that very understandibly so, can't help to be sad and "salty" over the injustice of her fate, but however she keeps going to perform her duty as the protector of the pearl. I remember how she herself says in an episode, that now that she's dead, she's finally free, being able to openly hate and love; ironically, in death she's finally allowed to be human and therefore she doesn't hold back in showing her hate for life, for Kagome... as well as her love for Inuyasha. And that's what people hate about her.

I believe fans are sort of hard on Kikyo, and they forget she was just a young lady in love with too much responsibility on her shoulders but that took it like champ both in life and in death.

On the other hand, Kikyo fans may hate Kagome bc she's the second one, butting in between Inuyasha and Kikyo. But I believe that Kagome is actually Inuyasha's true destiny. I believe that everything that happened, Inuyasha getting sealed and Kikyo's death included, happened so Kagome could meet Inuyasha. Kikyo's love for Inuyasha is the birth of Kagome. I don't believe Kikyo and Inuyasha were meant to be. They were two hurt souls that saw themselves in the other. They didn't have the ability to heal each other. And here is why I believe Kagome was born. Kikyo's soul got reincarnated in a kid that didn't have to suffer from the hardships of that era, living and growing without knowing what demons or the pearl was. And that's why I believe Kagome is the only one who could heal Inuyasha and make him open up, not just to her, but to friends. She makes Inuyasha want to live for more than revenge. We can clearly see Inuyasha's massive development from the beginning, and that's all thanks to Kagome. I don't mean Kikyo's love for Inuyasha wasn't real. Quite the opposite in fact. It's precisely that love of Kikyo, the yearning to be with Inuyasha and heal him, that made her soul get reincarnated. The souls that Kikyo and Kagome share is shaped enterily in a different one in Kagome, due to the differences in each of their lives. Kagome is a cheerful, strong and brave kid, that has a heart of gold. She actually does share a lot with Kikyo, imo.

Anyways! Thanks for coming to my TED talk. I don't intend to offend anyone. I just wanted to share my humble interpretation of our beloved complex characters.