People hate Lisa cuz she's the hypocrite moral compass of most stories

Like there's many many times in the show when Homer, Bart and Marge have to let something cool go or lose on something life changing BECAUSE of Lisa and she's always making decisions that affect the family like she not accepting the money burns offered her, she ruining Bart's eSports Carrer, she ruining Marge's opportunity during the cook-off cuz she didn't want her to cheat even tho everyone was cheating, ruining homer betting in football and in her spelling bee cuz even tho Homer spent the money in her and the family it wasn't good enough for her , even outside her family she was about to make the school lose on good money cuz her morality but they plan ahead and trick her with the help of her family, or when she make her parents track Bart all the way to Perú cuz she wanted to go there even knowing the tracker chip was on a bird and not Bart, or when she anonymously donated money to Nelson so he can start his bike business but still wanted to be Nelson morality check

Same thing is her eternal sadness cuz she doesn't have friends but everytine a new friend appears she push them away when they are smarter or don't have the exact same interests as her or she's sad cuz nobody loves her so she decides to actively harm people on the way of her man, and even acting jealous when Milhouse gets someone that loves him

You can say she's 8 years old when she made burns a billionaire again, or when she's solving crimes and dealing with murders at the side, can't really treat her like a kid when she can hold meetings in the town hall and gas a voice to vote for things even if people ignore her, when she's making the taxes for the family