Does that "unsafe to fly in controlled airspace" jibe mean that they're safe to fly in the open FIR or that they're unsafe per ser se? If the former, then the regulatory work being done should come to fruition, if not, then it can't happen.
UAS do a variety of tasks extremely well. The big issue for me is airworthiness. We have seen some early operational systems developed by small companies where airworthiness is bolted on at the end. Some of these projects have been taken up by larger concerns but at a late stage in development. Until the aviation world's big boys do a proper end to end job from first principles, there will be issues.
Similarly, as system experience develops, we will see increasing professionalism. This is particularly relevant where non-aircrew form the team. Technicians operating the UAS have an intuitive grasp of how the link is working, probably more so than aircrew. The big knowledge gaps are altimetry, met and airmanship from experience. I see training as the key to improved professionalism among operating crews.
And the unfortunate incidents are not limited to UAS as some of our more strident posters would like to claim:
BBC News - Review urged over BA plane runway error
Head below parapet.
bigv