"...do you really think thousands of hours in a manned aircraft and actual combat experience is a hindrance to succesful UAS operations?"
A hindrance? No. But necessary? Or even a worthwhile expenditure of training resources for the value received? Very debatable (despite your valiant attempt to portray the value received as indispensable). We're entering a new age of unmanned weapons, and we need new standards of necessary skill sets, as well as training, to operate these weapons.