Yes, if you really think about it, we've done quite a bit in our history with objects on strings, and yet a 20' string tied to helium balloons by the dozen doesn't require a pilots permit, and flying a kite doesn't require a license.
You don't have a clue what people are doing with these things, do you? Flying a unmanned aerial vehicle is nothing like tying a helium balloon to a string.
And naturally, the first question born from this insanity is why the hell aren't we forced to buy kite and balloon insurance these days...I'm rather shocked the greedy bastards let that one fly....literally.
You're not required to buy insurance for a lot of things, but you'll be personally liable for all damages without it. In the case of transportation, the risk of damage and injury is so great that the government has opted to mandate all vehicle operators be insured.