Etiquette is not a set of absolute rules but a convention worked out by the people involved so they can all best get along without incidents.
So any group of regular swimmers will evolve rules, this tends to work fine most of the time. Any newcomers will learn the rules after a few swims, and enjoy the swimming just as everyone else does. It is nothing to do with what you look like or how good you are.
I strongly suspect the writer is only making her points in order to have something to write about!
(as a regular lane swimmer over many years and different pools)