Chances are they’re only bereaved people waiting for the coast to clear before they can scatter some cremated remains.
It’s difficult to do that in public, openly. It might distress people. It’s not yet a socially okay thing to do.
The scattering of ashes is a ceremony often marked by awkwardness and secrecy. A pity.
It is also often done shamefacedly, in the wrong place. The adverse effect of ashes on the ecology of uplands is well attested, yet people go on doing it. Staff at Jane Austen’s cottage in Hampshire regularly encounter piles of ashes around the writer’s home and garden. This puts ash scattering right up there with dog fouling. It’s a poor way to commemorate someone, turning them into a bio-hazard. It’s not the sort of thing you’re going to feel good about.
There’s probably a very straightforward rule of thumb for choosing an appropriate location: if you can’t do it safely, openly and vocally, don’t.
The Observer ran a piece on this on Sunday. Read it here.