Tragedies have happened where cops have seen kids pointing what looked like real guns at people (like at the cops), resulting in the kids getting shot and killed.
That's the idea behind the red tips on toy guns. I think that anybody who wants to use AirSoft guns that look real must consider what could happen if they play around with them on the street, where they could be seen and mistaken.
Besides, AirSoft BB guns do eject projectiles. Anybody using an AirSoft gun should follow the same safety rules as for a real gun.