I've always found the narrative around Jill a weird one. People act like she's been totally absent from the series since RE3, but that isn't the case at all. She was in RE5, including having a prominent and playable role in both of the DLC expansions and Mercs (she's even on the box of every re-release since the initial one), one of the main characters of the first Revelations, and then obviously the recent remake. I understand not being a fan of the direction they took her, I wasn't a fan of her role in RE5, but like overall she's still been there and in a relatively prominent position in all the titles she is in. Hell, up until Revelations 2, Claire was probably even more ignored post-CV since she had zero role or mention in RE4-6. There was that first CG movie, I suppose, but Leon was the clear focus and her story was clearly the B-plot.
The problem isn't about them ignoring one specific character, it's as the OP says, they have just chose to focus so much on the male characters, specifically Leon and Chris. Jill's treatment is not particularly special since Claire was, for a long time, regulated to the abyss, Rebecca got completely ignored despite being one of the original cast members and even headlining a game at one point, and not a single female character they introduced post-RE3 returned until Mia in Village. So I don't know why people are so intent on just focusing on how she's been 'ignored.' It really should be something that is looked at as an issue with the series as a whole, not some weird vendetta against a specific character that people want to weave wild ass narratives about like the character being a mistake or crap like that.