As with other recent moves, such as the ban on adoptions by Americans and the criminalisation of blasphemy, the motive seems more political than moral.
Today such imprecations cause barely a batted eyelash (even if high-profile cases of perceived blasphemy still rile the devout in places such as Russia).
Because in France, there are all these freedoms, freedom of conscience, freedom of expression, freedom of journalists to make their choices, freedom of blasphemy.