I find myself asking the same question. Perhaps people are now too used to the rather hackneyed concept that higher beings must be brought down in some way because they're simply too powerful, too conceited or whatever (not much different IMO to the constant doom mongering we hear about modern technological advancement from some quarters), but I don't really see it as implied in the lore, and in any case, I would not see potential stagnation as adequate reason to sunder the entire star or for them to simply "move on" from their entire civilisation being wiped out. To the point that such a theme, including anything resembling 7's "cries of the Planet", would simply ring hollow with me.
With 5.2 as well as 5.3 and Elidibus's story and their events now concluded, my thoughts lean towards the entire war of light and dark being two well-intentioned parties entrenched in their position, itself born of a tragic event that hit a highly advanced society out of the blue, reducing it almost back to where it began without intervention.
In any case, I thought their interview commentary
here was quite good:
As was
this:
...and of course
this:
Almost all societal conduct is founded on "repression" to some extent, mostly because it facilitates mutual cooperation to do so (=is a method of establishing boundaries), and yes, they choose to channel their individuality and talents in specific ways. It makes perfect sense for a race endowed with their capabilities, and perhaps one they adopted after harsh experience taught them so. Further worth noting the English framing of it is rather particular, in referring to the Amaurotine as "patronising", whereas the French goes with "well meaning" or "kindly" (=charitable.)
Beyond that, Amaurot is implied to have held itself to a high standard (as per the dialogue of newly initiated citizens, particularly notable in the German edition; thanks to
Neila Nuruodo for these), so perhaps it was simply the price of living there. None of it really strikes me as an adequate reason to conclude they were going to collapse anyway, much less to justify sundering the star.
Given what we are now seeing with Fandaniel, I am more minded to believe something or someone had studied them well enough to understand how to bring them down should it exploit their anxieties by letting them, and by implication their creation magicks, run amok, and may have done so via the precipitating sound.