I think some people don't appreciate WHY not to pick up a mooring in fairly shallow water in a swell, as at the Baths.
I think people assume it's about swimmer safety.

Without the weight and catenary of a chain rode, moorings can only rely on the stretch of the nylon lines to absorb shock loads.
As I recall, maximum elongation of nylon is around 10-20%. A big boat lifted by the swell exerts tremendous force that WILL break the line if the ability to stretch is exceeded. That's assuming the anchor doesn't pull out first.