The Iron Giant and Superman by John Bryne
Without context, then yes I would definitely say those ratings are poor for the new episodes. Barely surpassing 1 million views is really low considering that Spongebob reruns can get an average of 3 million views per episode.
However, given how poorly nickelodeon has handled The Legend of Korra and all the marketing and advertising that comes with that, it honestly isn’t that surprising. The studio has allowed episodes to be leaked, which is something they have done many times before with ATLA and LOK, released a trailer for the new book only a week before it premiered, and has started airing the new episodes as hour long premieres, which shortens the presence of Korra on nick and shortens the build up of interest. When you compare all of this to the amount of marketing and build up they do for Spongebob it’s clear to see that they simply do not know what they’re doing. It’s incredibly frustrating and nick seems to almost want to see the show not succeed.
If you want to read more about how nick has failed this show, you can read this excellent write up by dongbufeng regarding nick’s inability to maintain a culture of fandom for Korra.