system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Wars] Why did Piett say they didn't need bounty hunter scum to a subordinate officer within earshot of Vader? Wouldn't that be viewed as insubordination of Vader's command?

It puts the subordinate officer in a bad place because he can't disagree with either of them. Also what was Piett trying to accomplish by saying that to someone who had no influence in the matter?
gpt
It was a power play.

By that point there was only really one force-user: Darth Vader. (The Emperor kept his Sith status as a secret.) The rest of the Imperial Officers were generally dismissive of the entire thing and showing up Vader was seen as a badge of courage. 

Consider:

>Admiral Motti: Don't try to frighten us with your sorcerer's ways, Lord Vader. Your sad devotion to that ancient religion has not helped you conjure up the stolen data tapes, or given you clairvoyance enough to find the rebels' hidden fort-... 

It was only Tarkin who talked Vader down from force-choking the Admiral. Even then Vader was subservient saying "As you wish..." showing that Tarkin had more power.

Basically, showing that you didn't fear this old, broken cyborg and his dumbass "Force" shit was showing that you believed in the power of the Empire, not the power of Vader.