This was a supply planet controlled by interstellar Ravagers.
There were 100 Ravager factions, and none were weak.
There was no clear hierarchy among the factions, but they adhered to a particular code. Few people were willing to provoke the Ravagers over a small matter.
If a person offended the Nova Empire or the Kree Empire, they could still survive on lawless planets that were under the Ravagers' influence and control.
However, if they continued to cause trouble in the territory of a member of the Ravagers, they would be blacklisted, and it would become very hard for them to fence loot and get supplies.
Of course, the definition of 'causing trouble' was very broad.
What Luke and Rocket planned to do could only be considered a personal grudge, which wasn't something that the Ravagers would bother with.
The main thing was not to start a large-scale war on the planet, like drawing battleships to the planet to bombard it.