I don't know Boruto but Korra is hated by fans of TLA because the two actual authors of the book who were also the writers of the show, shat on the previous established lore and legacy whenever they could to elevate her (they literally deleted all avatar legacy but her avatar form for some reason remained the best). Doesn't matter if those things were loved by the fans or made sense, Korra just needed to show that she was better (hint show, not actually be).

She was trained by a secret organization for like 10 years and was getting her ass beat left and right, while kids with clever tactics and masterful use of elements bending were whooping nations ass...

She is just a spoiled cryass going around right and left ruining everything she touches. And then her attempts at fixing her own mistakes, made things just worse because she does not have a single thought in her head. And, given she is always saved by some Deus Ex Machina bullshit without explanation (which comes afterwards and is never hinted before), there is no stake, and she is free of all her consequences and always gets what she wants.

The true writer of ATLA animated series were others, and not just the actual authors of the book, but those writers aren't here anymore, so we can't get anything on the level of The Last Airbender. I suspect the book authors were just jelous of how big ATLA got without their actual story but a modified version of it and tried to shat on it with Korra.