I agree. Just because it's low doesn't mean its poor. Can you give anymore details by the way? Im interested in having a nosey (Y)
Councils aren't likely to agree to anything too dangerous but its not insurance. They have enough insurance cover, but they probably wouldn't be prepared to accept liability if someone died (OK we all know its not likely, but its still possible). To put it another way, if someone died, Newspapers are likely to say:
"Council said 'yes' to project death and ignored safety risks!" referring to the park. Its not gonna look good for them is it? So to cover their backs they turned you down. Thats the impression I got when I asked my council anyway