As a responsible GM, you need to cater to the enjoyment tastes of all of your players. And hey, some players just love adversity. They can't get enough of overwhelmingly poor odds, ridiculously overpowered opposition, and virtually inevitable defeat.
As a responsible GM, it behooves you to provide this. Even if you're not entirely sure that any of your players are like this - it can't hurt just to make sure you've doing the right thing and have all of the bases covered.
R2-D2: This Vader thinks he's so damn good?
R2-D2: I'm the best at dodging in this Galaxy. I control the horizontal! I control the vertical! Just try taking a pot-shot at me!
[SFX]: Pow! [SFX]: Boom!
R2-D2: Okay, okay, you proved you can take a pot-shot at me. But I bet you can't hit that little hole in that grille over there.
Luke: Oh man. Oh man. Oh man.
[SFX]: < doip poppity bak-jang bing >
R2-D2: Luke, in case you were unaware, I'd flag those PIE fighters behind us. F.Y.I.
Luke: I know! I know!
[SFX]: < doop pating boodoot doosquee blip bloop fidooby tatap-jing doodle >
R2-D2: Let me level with you. We're in the last surviving two-bit scrap-bucket, on this suicidal fool's errand one-percenter.
[SFX]: < doosquee oodoo whroooop bedoop poppy >
R2-D2: We're up against the most powerful weapon ever built. The only competent entity on the mission has just been shot.
[SFX]: < kap bee-oop bing bak-jing be-zikuku >
R2-D2: And there are three highly advanced and ridiculously accurate fighters on our tail, closing fast.
Luke: So... You're saying we're screwed.
[SFX]: < pating bee-OO-oop >
R2-D2: I'm saying this is awesome!