What drives a poor reputation for the Rogue class?

[LudicSavant]

^ Adding to this - even if turn order and the ally's own desired tactics line up with your own, the enemy they're standing next to might not be the optimal enemy for you to be targeting. If I'm up against an enemy necromancer, doing extra damage to his zombie ogre minions standing in the front isn't bad, but I'd rather be targeting the caster standing in the back, especially when a big burst of damage from me might break his concentration more easily.

Yep, you got it!

The Swashbuckler using Panache to give a foe Disadvantage against everyone but himself has got to be just about the least selfish ability in the entire game

Panache takes a full Action, an all-or-nothing check, and breaks from distance (a la Witch Bolt) or... from an ally attacking or affecting the enemy with a spell.