Undoubtedly it helps the air quality that there have never been nuclear weapons detonated in it, among other things! Still, "we know better than you do what technology you should have and what your society should look like" makes me a little itchy - sure, there's no real option to let the atevi develop technology independently, since the humans are right there, but even just in human history sometimes a false start becomes really useful a few decades later, or a primarily militaristic technology has peaceful benefits. Then there's the whole "we will make the Ragi aiji totally solid and never going anywhere" thing - the East has functioned for centuries with one aiji being at best first among equals, and if it weren't for the humans wanting to get back to space ASAP that might be a better society. There's also "heretics" who believe everyone has (or should have, I'm fuzzy on the details) man'chi to everyone else and atevi society might be "better" if that viewpoint spread, even though that probably would make borders even more fluid and overlapping. (Or it might be worse - but with society forcibly centralized under a Ragi aiji, how is anyone to find out?)