There are virtually no documented cases of outdoor SARS-CoV-2 transmission. One study found one case out of something like 5,000 transmissions studied (might have been 3,000 might have been 7,000, don’t recall exactly right now) where transmission actually happened outdoors. This thing does not do well in sunlight or outdoor air that moves well.
Closing down every beach in the country probably prevents like 5 transmissions a month. It doesn’t make any sense and it doesn’t follow the science.
Then, how did the protests result in a surge of cases? The protests were not indoors...