Like most professions as soon as something different comes along our instinctive checklist says REGULATE, STOP, NO... or something similar.
It is absolutely wonderful that organisations are allowed to fly ex-military aircraft. This is an adventure market and not the public transportation/sightseeing market. People are not going to fly an EC120 if they want the Vietnam experience, they are not going to fly a Caravan if they want a blast in a Lightning nor are they going up in a C210 when all they want to do is dangle under a hang glider.
They are NOT competing with us. So why always complain about them? They put fun and adventure back into aviation - let them be and long may they last.