I quess we all are. But I can not think of a solution which would not lead to an outcry among the lightplane/-helicopter societies because it would either mean retrofitting costly avionics or implementing even more controlled airspace.
How about something far cheaper and less involvement of the bureaucracy and just teach good Airmanship Principles.
Heads on swivels, listening to the radio and conjuring up a mental picture of what is going on around you, checking above or below you when changing altitude doing cleaning turns if need be, and just plain old paying attention to outside the cockpit.
The Rule is "See and Be Seen! See and Avoid!