Forget the lightsabers and Death Stars—Star Wars is all about the power of friendship. There's the bond between Luke Skywalker and Han Solo, which has a classic little bro/big bro feel. There's the close friendship (and weird incestual courtship) between Luke and Leia. Also, who could forget about R2-D2 and C-3PO? We never thought two robots could give us so many feels.
The point we're trying to make is that the heroes of The Empire Strikes Back are all driven by their love for their friends, even when that love sends them hurtling headlong towards disaster, or Sith Lords. Usually Sith Lords.
Questions About Friendship
How does C-3PO and R2-D2's relationship affect our understanding of this film? Is it different than in A New Hope?
Why does Yoda think Luke's love for his friends will lead him to the dark side?
Why does Lando betray Han? What is another tactic he could have taken?
How has Han and Luke's relationship grown since A New Hope?
Chew on This
Yoda sees Luke's love for his friends as a negative because those same emotions could easily turn dark if something bad were to happen to them.
Because C-3PO and R2-D2 represented our gateway into the Star Wars universe in A New Hope, their separation in this film represents the worsening fate of our heroes.