Aldo
I do always carry and use an airband radio, this area was CTAF R so legally required to do so, and good common sense. In a previous life as cross country paraglider pilot where every flight was a cross coutry flight with an outlanding somewhere, we were continually on the look out for power lines and were (still are I think) legally able to fly well below 500' many a time have been able to scratch up into another thermal from just above the deck, or ridge soaring inches above the trees.
I dont believe ANY paragliders or hangliders carried VHF raios, seperation was purely visual with many pilots in very tight thermals, radios would be useless in this situatuion, so do you still call all paragliders and hanglider pilots fools?
Regulations are different for different types of flying, and what you may think is foolish in your type of flying is common practice in others.