"Why don't the bloody Zoners boycott Bretonia? "
Because doing so makes about as much sense as boycotting Corsairs for pirating our ships.
Zoners are not a House, we're a bunch of individual who have the CoZ as a quorum to talk over things. Even if we'd declare a boycott... what then? How many non-CoZ Zoners would even bother about it?
My only problem with QCP's action is their complete and utter refusal to even try and work something out behind the scenes.
They want to put pressure on GC for having corsairs there? Fine. Let them do so, but talk with the ones whom you are getting involved into your RP.
We could have the corsair factions and the CoZ and QCP sit together and think of a chain of events that would lead to something.
I also think from a RP perspective that angering the Zoners by attacking inside the NFZ makes no sense if they want to drive a wedge between Zoners and the Corsairs on the planet.
They should rather try to keep the NFZ untouched, or even favour Zoners doing trade runs into Bretonia (if they want they can just hijack the ships to bretonian ports) to cause political tensions on the surface.
All they are causing now is actually forcing Zoners and Corsairs to shoot at a common enemy... the completely wrong way to go about if you want to mess up Corsair-Zoner relations.