Well that's the Andalite's issue to deal with, not the Yeerks. The Yeerks shouldn't be forced to become something else or die. They did the same thing the the Yeerks that the Yeerks did to other species. While some may see that as karmic justice, it just doesn't seem right. It's obvious there were Yeerks who were in the same bind as the hosts they existed with. They either did what the government told them to do, or they starved to death.
I'm not arguing that the Andalites are right in any way by wanting to restrict/destroy the Yeerks. I guess the basic issue here is: who gets to decide the Yeerks fate? There are three main parties involved here: Yeerks, humans and Andalites.
1)
Yeerks: Well, they already decided their own fate, in a way, by forming the Yeerk Empire to begin with. But, post war, I would argue that if afforded the choice a great majority of the Yeerks would probably agree with you that their best option is to take voluntaries or maybe become
nothlits by their own will....but by no means have
nothlitism forced upon them. Of course then there will be other Yeerks, former Imperialists, who think that the Empire was right all along, which could majorly ruin things for the rest of the Yeerks. It doesn't really matter, though, because the Yeerks are the losers in this war, so they don't get to choose their fate anyways. The two real players are the Andalites and the humans.
2)
Humans: The humans are new on the galactic scene, and need to tread carefully. They need to appear strong without offending anyone (read: the Andalites). At this point the humans also have limited technology....VERY limited technology compared to their space-faring friends. While I am sure some humans would agree that Yeerks remaining in voluntary humans is acceptable, those humans in power would recognize that the important political move at this point is NOT to make the Yeerks and some humans happy, but to form a firm alliance with the Andalites. This means taking care of the Yeerks on their own terms (aka not frying them all), but still terms that are acceptable to the Andalites (hence forced
nothlitism).
3)
Andalites: I am convinced that after all of the propaganda that's been spread by the end of the war the majority of the Andalites peoples would be entirely satisfied to see the Yeerk race obliterated. Not through rehabilitation or slow genocide by way of
nothlitism, but by flushing/frying as many Yeerk pools as possible and/or forcing them back to their homeworld and setting up an Andalite guard that will never allow them to leave it. For the Andalites there is no other option. However, the newest player on the field, the humans, make their way impossible. They too need to form an alliance with the humans, however shaky, or risk bringing a new threat to the galaxy.
So....yeah....not that I disagree with you on what would be best for the Yeerks, Chad. It's that from a political mindset, from a post-war mindset, it's just impossible for that to actually happen.
And now I've yanked us entirely off topic. Oh dear.