And so, how would you say "Why Bother?" in Latin?
Well, before we can translate this, we have to determine--what exactly is the English even saying?
I mean, is this short for "Why should you bother?" Is it short for "Why should I bother?"
These things really matter in translation!
I think, and tell me if you disagree, that it's basically neutral. This statement is essentially saying "Why to bother?"
As such, I think we can express this accurately just using the infinitive "to bother."
But how the hell do you say that in Latin?
I searched a lot of resources and found that the closest match for this concept is the idiom "to move oneself (to action)." This is what John Traupman thinks is closest, and that's good enough for me.
Now it becomes a question of what word order would be most authentic coming from the mouth of that murderous psychopath Julius Caesar (who was, among his many "qualities" a native speaker of Latin).
Why to move yourself? (id est [i.e.] Why Bother?
For as fond as I am of how Spanish pastes objects onto infinitives (exempli gratia [e.g.] Quiero verte [I want to see you]), Latin tended to place the object before the infinitive. Even today in Spanish, Te quiero ver is grammatical.
Ergo, my suggestion for how to say, in Latin, "Why Bother?" is:
Cur te movēre?
That's my rather educated guess, but don't tattoo it onto your body just because I said so...