Hi Diving Gecko,
I was pole-spearing in Okinawa 2 months ago. Didn't have any issues at all with the locals. Maybe it's the spot you went to?
I was diving mainly on the west coast early in the morning around 7am. Managed to catch some decent sized horse eye trevally's.
Let me know next time you head to Okinawa, I can point you in the right direction