On the one hand, it's a bit unfair that The Core ID is the only ID that can't take caps out of it's ZoI (Order ID does technically have a similar limitation, but the Order ID doesn't have a ZoI), but on the other hand it's to stop indies chasing down Order and Nomad players down Sirius wide with Makos, which would cause big diplomatic fallout and probably annoy the players. The line is just a preventive measure, and does that job well.
In my opinion I still think that all IDs with capital ships should reccive the line, as it's logical and saves headaches.
On thing I've noticed though is that the line could be interpreted as you not being allowed to take Gunboats out of your ZoI, which is unintentional and will hopefully be corrected.