^
That wasn't something they did by choice though; Revenge of the Sith seems to imply it was a genetic predisposition that all the clones were programmed/grown with by the (secret) order of Palpatine...
How is this at all implied?
They're soldiers, given a direct order by the supreme ruler of the entire galaxy. More than that, this guy might as well be god to them, since he's (in part) responsible for their very creation. He calls them up and says "The Jedi have tried to take over; they're enemy combatants and should be considered target zero." It's their job to kill the enemies of the state, and that's what they do when they turn on the Jedi; no mind control required.
Fair enough. But even a soldier will at times question their orders... the Clone Troopers don't seem to have that problem.
As you said, Palpatine may as well have been God to them for how they so easily and blindly followed orders.
Is there a rationale for why they follow Order 66? Absolutely -- you just provided it. However, that's not what we see in the film. Had Palpatine said to the Clones, "Hey, the Jedi are stirring up some shit and I need you to take them out to keep the peace" that would have been at least defensible... but Palpatine doesn't do that. All he does is say to all the Clone Troopers everywhere "Execute Order 66."
What is Order 66, exactly? We don't know. Lucas probably wanted something ominous for that fraction of a minute between the line reading and the first slaying of the Jedi. But that's pretty much what happens and next thing you know, the Jedi are being turned on and slaughtered.
I'm not saying it's mind-control. I'm not saying it isn't what you say it is. Ever since seeing the film five years ago though, my general interpretation of that scene was always that when Palpatine ordered the creation of the Clone Army, he had an added "feature" to ensure the clone army's loyalty to him, including the bit about programming them to respond appropriately when Order 66 was issued.
It's sloppy writing to be sure. Are we to assume then also that all the Stormtroopers in the original trilogy are in fact just more clone troopers, just later? Or are they individual, "real" people? If they are clones, do they still have the susceptibility to follow Palpatine's orders, or could one of them --if they so chose-- rebel? Wasn't Han Solo originally a cadet in the Imperial Academy? Could he have been a storm trooper, or was he aiming for one of the Star Destroyer command jobs?
Admittedly I don't know enough about the inner workings of the Empire command structure, but if I'm wrong I'll gladly relent. I just never considered that Palpatine
hadn't programmed the Clones to his advantage, much like the Founders did with the Jem'Hadar and the Vorta. It just makes tactical sense.