Should it??? Point me to a real world conflict example where a country will accept significant and cumulative destruction of its economic transport fleet (in real world examples commercial shipping and commercial air) EXCEPT in existential type conflicts...
Britain and Japan accepted it in World War 2 as they were locked in life and death struggles...nobody is going to accept it over petty border-struggles at a level BELOW that of full-conflict...
Which is what PP struggles ARE...
There's NO state of War between the Federation and the Empire (much less between factions of the Powers) its a "cold-war" type struggle of economic conflict, political maneuvering and low-level insurgency
This is actually another good point, which has been highlighted many times previous. Another issue, which should be resolved as well.
PP factions are warring factions amongst each other within the scope of the "big 3" factions (Fed/Emp/Alliance) and RL examples are usually dismissed "becuase it's a game!" yet there's precedence for commercial protections via treaties and such. Germany broke this but this was considered a war crime, as it violated all treaties made by countries prior to WWII.