It kind of surprises me that people think that democratizing power and technology cheapens it. Unless you have some nostalgic romantic view on the world, democratization of power and knowledge is what separates our modern world from the shithole that our parents, grandparents and prior generations had to endure.
We live in the best times in human history, there is no denying that. The world of Avatar went through the same transformation. Democratization of knowledge doesn't magically make everyone happy, and creates a whole new slew of conflicts, but at least it gives more people access to determine their own fate rather than having some war mongering elite kaste monopolizing knowledge to themselves exclusively.
Ultimately Zuko, the Earth King were little more than tyrants. Despotic rulers who monopolized knowledge and power to enforce social shisms and segregation.
Ba Sing Se, and the Fire Nation Society expositions were a clear indicator of that. Benevolent or not, the world of Aangs time was ruled by dictators and nobility while the rest of the population lived in servitude and constant insecurity with no legal representation or status.
It's no coincidence that the series started out in a tribal community that served as a juxtaposition to the other nations.
I for one am fascinated how the series creators made the bold move to actually go to such lengths to think about how the world and it's problems would change if bending became democratized. It created a new social kaste that is determined by genetics and with that new conflicts. But instead of people now being unable to advance because of social segregation, the new found liberalism allowed for non benders to develop mechanical weaponry and gadgets that are able to even out the power/potential level between benders and non benders. Tarrlok being a criminal thug, rather than some puritan messiah of the oppressed is a much more believable revelation and shows that the storytelling and world of Avatar has matured beyond a point where characters aren't mere cardboard cut outs that have to fit into established stereotypes and tropes anymore. In some way it reminds me of the cult around Che Guevarra or other murderers like the RFA or the who used their charisma and the pretense of fighting for the masses to legitimize their criminal actions.
Compare Korra to this background, she's a young outgoing girl, but at the same time a relic of a world that no longer really exists. It's not her being the Avatar that makes a difference, it's her becoming a well meaning caring individual that takes responsability for herself and her powers that makes her make a difference. Just like all the other characters in the series like Asami or her father do. I still maintain that Korra is a well developed character, and I absolutely believe that not everything has to be spelled out to be effective story telling.
Anyway, I do agree that the cramped mini series style was an unfortunate decision. It didn't allow for some interesting tangents to be explored and I really hope that the new projects can remedy those aspects.