I can't think straight since I was working pretty late at night again this week. Then, I got hit by my allergies. My reply will be short. Your views are piracy is great and was from another angle I haven't seen, neglect. For me, what I observed is that piracy comes from fans who want to see a show or read a manga but it's not available in their country legally. They have to resort to any means.
That's the demand behind fan scanlations. All these manga series, only a fraction gets licensed for countries mostly western outside of Japan. Countries like in Africa and many others who are small in demand will have to resort piracy. It's not a choice for them. In the states, you have more options. Like you mention, these legal sites, Crunchyroll, FUNimation, HULU, and Netflix have their limitations of what they pick up. Despite there is competition, folks benefit from competition because it normally lowers price for them. In this type of marketing, subscribing isn't going to let folks to freely sample each company and save money. As a mod, I have to stick with promoting things legally in the site. It's an oath we sign. I only violated once for one show.
I feel the same way with anime. It's more easy for me to identify with video game interest in public than anime. I do see people treating anime as children show or as adult porn. It was never in the middle. I talked with friends. Most of them are not into anime like I am. They share stereotypes of anime. Most of them are gamers or comic book lovers.
For Korra, each Book feels separate o how they are constructed. You end the book by defeating the villain. Avatar had a book villain and overarching story with the big villain at the end. I agree how it Avatar felt more complete than Korra. I hope this universe generates spin-offs and such. It has build something with plenty of material and potential for fans, new and old, to enjoy.