Buffy Summers propaganda!
I don't know how it is now, since I've sworn off Buffy reddit and I only interact with the fandom in my highly curated tumblr bubble, but back in the day, oh my god. People constantly called her annoying for complaining too much about being the Slayer. If you're not familiar with BtVS lore, I cannot stress enough that being the Slayer is easily one of the shittiest Chosen One gigs in all of fiction. You get chosen when you're a teenager (Buffy was like 15!) and you do get superpowers, but you're not like Superman level strong or anything. You're the only Slayer in the world (unless some shenanigans happen) so you don't even get to go to like a special school for fellow Slayers or anything. Buffy's doing all this shit and she still has to attend regular high school. Also, there's no specific threat that you've been chosen to solve, and once you solve it you get to chill. No, you have to fight a never-ending slew of monsters who are constantly threatening to do an apocalypse until you inevitably die a horrible violent death, probably before you even reach the age of like. 20. And the people in charge of you don't actually care if you die (in fact there are times where they actively encourage it) because the moment you die some other poor girl will be called instead of you. So even though you're technically "special" you're also a completely disposable sacrificial lamb who exists to have a short violent horrible life and then die young, only to be immediately replaced. And if you refuse to fight the monsters, the world will end it will be your fault.
This is the fate that people called Buffy whiny for complaining about! They saw a young woman resisting a system that was built on exploiting her labor and that she knew would eventually result in her horrible untimely death, and complained that she wasn't stoic enough about her fate or compliant enough with the system.
Spoilers for a 30 year old show incoming, but there is still a huge contingent of the fandom that thinks the show should have ended in season 5, a season that essentially ends with Buffy giving up, fully submitting to her role as sacrificial lamb and basically committing suicide (to save the world and her sister, but also she's just really depressed), because they can't stand seeing the final two seasons, where Buffy is brought back from the dead and is messy about it, and is an imperfect victim, and she's just so mean to the fandom's vampire blorbo (personally, as a Spuffy season 6 enjoyer, I think she should've been meaner to Spike actually).
Now, to be fair as much as I love season 6, it is very flawed, and most of season 7 does just suck, so there are valid reasons not to like those seasons. But still, I genuinely can't wrap my head around how you could possibly prefer the ending where Buffy just accepts her horrible fate and kills herself to the actual ending we got, where Buffy finally manages to re-shape the system, so that it's not one girl who's the Slayer, but a whole bunch of them, who can work together and protect each other and take days off and generally massively increase Slayer life expectancy in the process. Hell, some girls can even choose to not fight at all if they don't want to, because no one person is responsible for the fate of the world anymore. Buffy doesn't just save the world, doesn't only preserve the status quo, at the end of the show she changes the world for the better. It's maybe my favorite ending of any show ever, and inexplicably there are people out there who wish the show had ended with Buffy committing suicide instead.
And maybe some of them just really hate the final two seasons, and again, that's fair (although I personally really do love season 6!). But I do think there are people who don't like that Buffy refuses to accept her fate, refuses to conform to the systems that have done so much harm to her, refuses to be the stoic hero who just accepts that she's been chosen to set herself on fire to keep everyone else warm. There are people who want her to just stop whining and accept the world the way it is, even though the way it is is actively hostile towards her. If you can't tell, being a Slayer is often used as a pretty unsubtle metaphor for like. being a woman in a patriarchal world. And it's not always a great metaphor. I mean as you all probably already know, Joss Whedon was not actually very good at being a feminist, to put it mildly. But sometimes that metaphor actually does work really really well, which makes it all the more infuriating to see people complain that Buffy whines too much about the patriarchy, basically, and won't just accept her life the way it is.
Anyway, I have gone on for far too long about this, but I'll end this by pointing out a few other ways people are misogynistic about my girl. Like the propaganda in her poll says, a lot of people reduce her to a prize that their favorite love interest should win, even though, for all the flaws in the writing, Buffy is easily the most interesting and well-developed character in the show. Also, there is still a subset of fans who love explaining that it's actually her fault that Spike tried to rape her. It used to be a much bigger contingent of the fandom, victim blaming is not quite as socially acceptable as it once was, but I still see this take pop up, and as long as people make these claims using woke enough language, it's unlikely that the person saying these things will even get much pushback about it.
In conclusion, Buffy Summers is the greatest character in all of fiction bar none, and even though things have gotten a lot better recently, the fandom has still spent like 30 years being weird about her.
buffy summers propaganda!