On the actual topic, there are more zoners allowed in Gallia then not allowed. OSI was the first group allowed in back in 4.85, JZ and Phoenix in 4.86 quite recently.
Thing is, whenever I was on my GRP, what to know what type of zoner I saw? silent traders who mocked the king or disobeyed laws, warships or zoner battleships used as jumpships.
Now I've only met 2 non group/factionized zoners that were actually cool and RPed it well. The rest disregard everything Gallia stands for, RP wise. So if you want to really want to know why people sometimes blow you up, think about that.
On the other hand, I'm currently attempting to sort out this problem via what Doc Holliday has started, seen here.