Whatever the show's flaws, I do think her having most of the elements down at 4 was part of a genuine attempt at characterizing Korra as entitled and immature, showing her the same at 17 as she was at 4. Not the only purpose, but part of it. It may have been undermined by the writers' own beliefs, but it wasn't actually a grrl powah moment. The egregious strong women schtick was more ATLA's thing.

The issue in Korra's characterization is that, no matter how wrong she is, somebody else is always more wrong, either because they're suddenly written as nutcases, or just because they made Korra feel bad. The consequences she faces are only shown for brief moments, being reversed very quickly, while the focus is more on how her feelings, no matter how quickly they change, or how much of them are self-inflected, are valid. None of this is for propaganda reasons, but because the writers themselves are woke. I think they actually wanted to write Korra as troubled, but simply weren't capable of it. This is actually how progs interpreted troubled women in the early 2010s.

Where Korra does most of its propagandizing is in its proto-liberal patriotism. You can smell the Obama voters on the script. It's all about how cosmopolitan liberalism is so plainly the sole intelligent and moral belief system that you'd have to be evil or retarded to choose otherwise. Even if you recognize and attempt to fix flaws in the system yourself, you, as a pleb, will inevitably fuck it up. Only a true priest(ess) of liberalism can integrate your beliefs, and only insofar that they can be interpreted as an extension of liberalism, rather than a criticism of it.

There's definitely a connection between Korra's characterization and liberal patriotism, because one is the product of unchecked female narcissism and the other is fueled by it, but that's a whole separate wall of text.