I can understand the frustration when you're looking for a fight and the faction you feel should want to fight you actually doesn't. But that doesn't mean that they are wrong.
The thing is maybe it isn't a good idea for them to fight you there and then. Maybe there are low on resources, maybe one of their crewmate is lagging at that moment, maybe they try to find a advantageous spot but you never allow them to find one etc etc. When you allow people to flee, you allow them to chose when they fight. They will fight if they think that their reward is greater than their risk.
Either you force them to fight by attacking them properly (cutting off their escape route) or you entice them to fight you by making it seem like you are worse fighters than they are.
You already can do that. You don't need the dev's to do it for you. ;)