Character Analysis
Cyclops Is Tops
Like Thor, Odin comes from mythology, and a lot of his traits are ported over straight from Norse mythology-land. The OG Odin had one eye, raven spies, and even an eight-legged horse…which is why he gets that weird shot of his horse in Jotunheim.
The movie sticks close to those details, but emphasizes the whole "king" part in the "king of the gods" job description. He's got responsibilities: Asgard depends on him for safety and, while he thrashed those frost giants good back in the day, he's not exactly eager to go to war again.
He's learned what kind of horrors that would unleash, and he's not about to let anyone start that up again…least of all his tantrum-throwing son. We get this early on, when he tells the very young Thor not to get too big for his britches.
THOR: When I am king, I'll hunt the monsters down and slay them all! Just as you did, Father!
ODIN: A wise king never seeks out war. But he must always be ready for it.
Words of wisdom from daddy-o.
And as part of always being prepared, he has to get his son ready to take his place. He may be a god, but he can still be killed (though it's presumably extremely tough), and he may eventually die of old age as well. That means sooner or later, Thor's going to get the big seat, and when he does, it's Odin's job to be sure he's ready for it.
Clearly that's going to take some tough love: Thor's kind of a jerk, and a guy like Odin cannot have jerks taking his place.
ODIN: You are a vain, greedy, cruel boy!
THOR: And you are an old man and a fool!
ODIN: Yes... I was a fool, to think you were ready.
So he tosses his first-born to New Mexico to teach him a lesson. He hopes and wishes that Thor will grow up, but realizes that Thor is too much of a lunkhead to do it from the lap of luxury that is Asgard. Unlike Thor, he's not doing it out of anger (okay, not much), but because it's necessary to get Thor ready for grown-up duties.
As Frigga puts it:
FRIGGA: There's always a purpose to everything your father does.
That makes him a mentor similar to Gandalf (he's even got the beard to prove it): an old man weighed by a huge burden. He knows that with great power comes great responsibility…and his main job here is making sure Thor figures that out.