I'm talking about a straight-up shot for shot remake with current animation.

Yes, the live-action version that exists is garbage, but there's only two ways this live-action series ends up.

1. They keep every single aspect and plot point the exact same which wouldn't be as interesting and make the entire project a pointless money grab.
2. They actually change things to make it a new experience in which would likely result in at least half of you mad over every single change no matter the quality. Keep in mind, with new actors performances will instantly differentiate from the show no matter how good they are.

One thing there's an overall consensus on with Korra is the fighting and bending were better. This is in large part due to the advancements in animation between the two series. Remaking the original series with better animation would introduce the story to a new audience and satisfy the existing fan base.

Edit: Yes, I would much rather them expand the universe and world build. I'm saying if they're going to rehash these same story, this would be a better option.