Hehe, it could be considered a minor easter egg
Back then when we were working on the demo, we've created the swarm of flies. Actually they were even in the demo world (a bit behind the starter cabin). We have some future plans to spawn them naturally in the world (either spawn them randomly, or at some points of interest [e.g. buried chests], or near dead bodies etc), but until then, we decided to spawn them at 0 0 (considering this is always in the middle of the ocean, so likely they shouldn't interfere with any buildings etc)
somewhat related question, is there a reason why the player doesn't spawn at 0,0, red? it seems logical to me that the center of the world would be the main spawn and i've always wondered about that. i think in ark the reason was that 0,0 sometimes got a little... weird?