And what would you propose be done? Short of outright banning UAV op's, because that is never going to happen.
We have rules, reg's, radios, ADS-B and every other sort of thing and we still have mid-air's between full size aircraft.
Nothing will ever be perfect.
Personally I'd like to see UAV op's on TIS-B, but the FAA says that'll never happen, that it'll overwhelm the system no matter how you get that data, via ADS-B or otherwise. I'd also like to promote a nationwide "DTAF" freq. so that you could coordinate if needing to enter a DROTAM area, but that isn't happening either. So in the meantime we've got the magic 400 foot rule (in the US). Best be aware there are both plastic and flappy birds below that altitude, and occasionally above that as well, unfortunately.