I will say this it is very hard to write women as characters, even for women writers, just think about it, when making a show for girls we have a female lead who most of her problems are girl related ones. If you want to have a show for boys you give it a male lead, and if you want a show that can be for either girls or boys, 9 out of ten times it's still going to have a male lead. I'm sure you can come up with a lot of examples to disprove this, but I'm sure you can find a lot more examples to support this. Now the original avatar was a show aimed for boys and girls and had a male lead, so the question is could they change it to a female and still keep the same audience.
Well I don't know because I have no idea what the male to female viewer ratio is for this show maybe a lot more girls like it than boys or maybe boys can actually relate to her in spite of her being a chick.
Personally I don't see why they wouldn't. Most of her problems are one's that both boys or girls would understand. She needs to save the city and that's where the focus lays. Her choices, her actions, much of her personality is pretty much interchangeable if you put a guy in that situation. Even the problems that she does have that are girly like trying to get a guy to like her is still interchangeable if you just replace the guy she likes with a girl. this is definitely a step in the right direction to writing a great female lead but it's not completely there. I wish that they would give her more girly features to focus on, because she is a girl. Not too many, if you give her too many than male viewers might feel isolated, but some. In shows with a male lead we do see problems that are usually just associated with boys when they show is targeted at both a male and female audience.
for example there was this one scene she was in where she tries to put powder on her face and it's very obvious that she doesn't normally put on make up and doesn't know how but is curious and maybe thinks it would make her look pretty, so she just slams it right into her face. That's a funny scene that probably wouldn't work for a guy or at least work differently. I would love to see more scenes like that.
I don't know, like I said I don't know how many boys vs girls like this show. Are there any guys out there who find Korra to be a relatable lead focus? Or like her simply because she's hot? Or don't like her for any reason?