This is more of a game-wide question than specifically a thief question – but what do you think about weapons that, in particular, have autoattacks that are designed for AoE and do really bad single-target damage? In this case we’d be talking about Shortbow. It’s present on some other weapons also, like the the lightning attunement on Ele staff, and Ranger’s axe.
My thought is that there’s no real legitimate reason why these should be so bad against a single target as it only succeeds in making the weapon useless in situations where it doesn’t need to be. Why not make Trick Shot do more damage against the initial target, and then the same it does now to additional targets? I’m not saying it should do the same amount of damage as a truly single-target skill, but it should do more than it does currently.