That seems kind of out of character for Farnsworth. Isn't it more likely he'd want to save Hitler's brain or eat Hitler's brain or make some kind of impractical star weapon powered by Hitler's brain...
I could see him getting off on the rush of godlike power one would feel upon killing a major historical figure.
Not that I'd know from experience. Not a chance that Kennedy was supposed to end the cold war in 1966, redistributing massive amounts of military dollars toward the public good in the aftermath, leading to the eventual creation of a perfect society. No sir.
This isn't a good joke. Not by an stretch of the imagination. I understand the cartoon robot drinking beer at the beginning might of had you confused that this would be funny, but it wasn't.