Gnawlrighty then, here's my take. I'm speaking as a Yeerk, addressing humans, here. Jessi, if you happen to make your way in here, I hope you don't mind my stealing of some of your words and ideas.
You make us out to be evil. We are not evil. You call us destroyers, but we seek only to protect and improve. You make us out to be slave masters, but we are your liberators.
You place far too high a value on what you call your 'free will,' human. As a human being, you have a lot to gain from one of my people. Think of how little you'll have to worry about, about how much better off you'll be-- you'll have the resources of the whole Yeerk Empire at your disposal. Think of what we could accomplish together. Two heads are better than one, as they say. You get to keep your sight, your feelings, your thoughts, nearly all of your freedom. All we take from you is a little control.
On your own, you humans are a violent, unpredictable species. You cannot even manage to exist together in a single society. You fight each other constantly, over land, over resources, over what you perceive to be right by your religion, over skin color. Murder and greed run rampant. While your poor gun each other down, your rich sit back and watch as they die of starvation. Tell me, where's the free will for those innocents who are killed? Tell me how much choice you really have in life, human.
We will eliminate all of that, when we take your planet. Yeerks do not fight wars with each other, do not kill each other over conflicts (with a few notable exceptions). We do not allow our hosts to starve in the streets or be murdered for no reason at all. We will free you humans from all the dangers of your so-called culture. With us in charge, Earth will never again see the likes of war, crime, disease, prejudice, violence, fear, slavery. We Yeerks place a higher value on the lives of you humans as our hosts than you do on each other.
You see it everywhere in this war. If it were left up to us, every world would all be taken in much the way the Taxxons were. There was very little resistance, very little Taxxon death, comparatively speaking. The only known Taxxon rebellion, the only cause of the loss of Taxxon life on their homeworld, was led by an Andalite. We have raised the Taxxons to being so much greater than they once were.
Now compare that to the Hork-Bajir homeworld. Our infestation of the Hork-Bajir would have not only kept most of the population alive, it would have brought them to the stars. The idiot Andalites thought much as you do-- that the freedom of the Hork-Bajir should be valued more highly than their lives. It was the Andalites who decimated their race-- once again, we see a case of the great Yeerk Empire improving, and the Andalites destroying. When the Andalites come to Earth, do you think they'll be the ones defending humanity? Or do you think they'll simply try to wipe you out, to eliminate humanity in its entirety? And when they try to wipe you out, who's going to stand in their way, if not the Yeerk Empire?
Really, what's the alternative? We go back to swimming, blind and helpless, in our pools, while the Andalites strut about the galaxy in their technological superiority, and you humans go back to killing each other for oil, and you all continue to abuse the bodies and the sight that we've been denied? Explain to me, human: where's the "free will" for my people then? If we allow you humans to continue to choose whether to watch football or porno, we're denied the ability to learn, to have a culture of our own, to grow to our potential. We're denied our entire world.
We can't help what we are, but we can do something about our lot in life. We can only do what we were born do do. Don't deny my people their lives, simply because you place too much value on your illusion of free will. Good Yeerks are wasted in the pools, living and dying without ever once seeing the sun. We've been gifted with the ability to take control of other species, and the intelligence to appreciate them. We are not going to ignore our gifts and live our lives unfulfilled. My people deserve so much better than that. My people deserve to be allowed to travel the stars.
Don't think of yourselves as slaves, human. Think of yourselves as children. Left to their own devices, your children will eat glue or jump bikes or wander into traffic and wind up hurt or crippled or dead. You don't let them do those things, because, as their parents, it's your job to guide them until they know better. Even if they kick and scream and cry, you'll do what's best for them. You humans, you're children. Left to your own devices, you will fight and kill and decimate your planet's resources until there's nothing left. We are here to guide your species, human, until you realize that life with the Yeerks was always the better option, and stop kicking and screaming and crying. But that can't happen as long as there are still free humans out there espousing the benefits of 'free will.'
And we will fight, human. I will fight. The Empire will bring a better life to everyone, and we will not stop... I will not stop... until we've taken every last one of you.