Just an opinion, but I think the ban was an emotional reaction to the wave of Islamic terror attacks in France. We shouldn't expect people to remain coolly detached when their lives and those of their family and friends are under threat from murderous, religious fundamentalists.
It was the wrong reaction.
While there's every reason to ban hijabs, burkas, and other face coverings, which can be used to hide the identity of terrorists, forcing Muslim women to use normal swim wear at the beach is a denial of their democratic right. (A democratic right that terrorists use to commit their atrocities.)
The Catholic Church was guilty of organised legal terror during the years of the Inquisition, and the protestants fared no better in Salem, Massachusetts. And, of course, there was the infamy of the Crusades. But this is the 21st century. The Christian church has moved on while Islam wallows in the ignorance of the Middle Ages.
When you think about it, just 100 years ago, even western society insisted on covering up. We've come a long way, thank goodness.