They could have stayed home, but what would you do?
Are all gasoline generators necessarily noisy?
In past years we had a good paying gig at a private picnic, where there was not power available. We negotiated for them to pay us to rent a small (Honda, IIRC) generator, to power our PA. Placed 50 feet away, with an extension cord to it, it was not loud enough to bother us in playing the gig. Do these people not have mufflers on their generators?