This is because he's never seen it.
He didn't write it. He didn't direct it. He's never seen it.
Looking back, it makes sense. There are parts of Return of the Jedi and the prequel trilogy that ignore, parody, and even contradict the events in Empire. Some of them are so egregious, you start to wonder if you know the film better than the film-maker.
Well, if you've seen the Empire Strikes Back once, congratulations: you know the film better than the film-maker.
Here are the first two pieces of evidence in my ongoing research:
1. The protagonist's character arc is resolved off-screen.
2. George Lucas thinks Yoda speaks like a Yoda impersonator.
Dumbledore could raise a spaceship out of a swamp, if he wanted to. Same goes for Professor X, Gandalf, and any mentor worth his mana. What makes Yoda special is that he seems insignificant.
Yoda lives on a compost heap that’s the size of a planet. His forehead has the texture of a diseased scrotum. He sounds like my Jamaican house-keeper...and his grammar’s just as lousy.
Always swaps his phrases, does Yoda. Strictly followed, is this rule.
Yet when he raises the spaceship, profound, the moment is--and impeded by clunky syntax, it is not. Curious, I find this. Revisit Yoda’s monologue from that scene, we should.
“For my ally is the Force, and a powerful ally it is. Life creates it...makes it grow. Its energy surrounds us and binds us. Luminous beings are we--not this crude matter! You must feel the Force around you: here, between you, me, the tree, the rock...everywhere! Even between the land and the ship.”
Grammatically, that ain’t bad. It reads like faux-Shakespeare. You can imagine Peter O’Toole performing it in a toga.
The screenwriter seems to use phrase swapping as a rhythmic device. The monologue sounds less like a Mad Lib, and more like...well...a monologue. The result is a scene that’s more profound than anything George Lucas has written, could write, or would want to write...which must be embarrassing.
Fortunately, Yoda precedes the monologue by asking, “Judge me by my size, do you?”
"Judge me by my size, do you?" is much easier to (1) remember and (2) print on a t-shirt than all that “surrounding and binding” hogwash. Since t-shirts and second-hand accounts are George Lucas’ only exposure to the Empire Strikes Back, he thinks that “Judge me by my size, do you?” is the gold standard of Yoda lines. Check out this gem from Return of the Jedi:
“Do not underestimate the powers of the Emperor, or suffer your father’s fate, you will.”
Here, Yoda encourages Luke to succeed where his father has failed. That’s a powerful sentiment, but Lucas clearly typed it into an online translator, and then translated it back into English.
Keep in mind, Yoda says this on his death bed, and every word is a struggle. Yet instead of striving for profundity and concision, Lucas prioritizes phrase swapping. Clunky, jarring phrase swapping. Thank goodness Yoda had settled his affairs.
Master, who’s inheriting your hut?
Yes? Go on...
Inherit my...my hut, shall...shall Lllll...
“Shall Luke?” “Shall Leia?”
Luke or Leia?!
Admittedly, Yoda does a lot of phrase swapping when he’s introduced in Empire, saying things like, “A powerful Jedi was [your father],” but only because he’s concealing his identity to test Luke’s character.
When Yoda's sure that Luke is indeed a pissy bitch, he reveals his identity--and he does so by speaking grammatically(-ish). “I cannot teach him. The boy has no patience. Much anger in him, like his father.”
In this moment, we learn that Yoda plays up a speech impediment to make people think that he’s dumb.
Bearing this in mind, let’s “rewind” to the prequel trilogy. Yoda is one of the most public figures in the galaxy. He leads the Jedi Council and commands legions of the Republican army. Heck, he’s an inter-planetary diplomat: “Go [to the wookiee planet], I will. Good relations with these wookiees, I have.”
When commanding soldiers, he orders, “Around the survivors, a perimeter create.”
When promoting Obi-Wan, he explains, “Confer on you the level of ‘Jedi Knight,’ the Council does...but agree with your taking this boy as your Padawan Learner, I do not.”
When dueling with the Emperor, he quips, “At an end, your rule is, and not short enough, it was.”
So if Yoda can persuade a planet to go to war...if he can lead troops to death...if he can preside over a religion of telepaths...if he can duel for the fate of the fucking galaxy...
...why is he playing the fool?
Because George Lucas didn’t know that Yoda swapped phrases as a defense mechanism.