I have enough voices in my head that if we all rallied together we could confuse the yeerk to death.
Seriously thought I'd probably be voluntary, you have to imagine that the people in the sharing aren't getting the whole story, they find out all the cool people they've been hanging out with are controlers and a very simple logic is posed to them: the yeerks come in peace and only want to borrow some bodies to help them out since they haven't got enough bodies of their own.
Maybe they don't say they're at war, maybe they don't say they're conquerers if they do, maybe they're the victims instead and they need you to help them. Tom once presses on Jake the issue of being part of something big that may well have been the yeerk campaign, you the host help them with something big, see the stars, you don't have to know you're trying to conquer the world because the yeerks could make a convincing argument that they weren't trying to conquer the world, just looking for recruits. If they wanted to conquer the world they'd just do it, they have the technology.
Visser 3 being a jerk is just a case of having a bad boss, nobody sees him before becoming a controller anyway, those who do, like Tom, become controllers whether they like it or not. But for the majority they're probably offered adventure, a star was/trek like adventure and most kids and young adults would jump for that, I myself if I didn't know there were andalites or anything like that would be all for joining the yeerks, and as others have said if the yeerk in control isn't a total jerk since you can't read the yeerk's mind the less you see of their "bigger scheme" the less reason you'd have to fight.
Being able to laugh and watch TV in the yeerk pool makes this theory hard to buy but I for one think that's what would have been the reasoning behind a lot of people choosing to be voluntary controllers, and your own yeerk could have explained away the screams if you bought their other lies why not buy this one: The Hork-bajir aren't intelligent, they're like chimps really, semi-sentient, they can't even speak full sentences, don't mind their cages, it's because of how dangerous they are. Screaming humans? Oh well some yeerks abuse their hosts and the hosts don't trust any yeerks after that, but can't be set free and so have to be tragically, contained while their new, nicer yeerk feeds until they realize that the yeerks are friends of humanity . . . speaking of friends, sit down and relax, watch Friends and don't make waves, little human.
