I agree with you aroa. The only reason CAsA could have to regulate commercial aviation is because the ignorant and unwashed can and do climb aboard.
With a "drone", this is not the case, so regulation should be solely on the safety case which is independent of whether or not money is deemed to or actually changes hands.
In my opinion, the case for regulation can only be made on the basis of the population density of the region of operation - i.e. the likelihood of proximity of unsuspecting non-participants.