Why would that make it more common in the UK? Being able to bring a private prosecution strengthens the distinction, a regular citizen can both sue someone for

Why would that make it more common in the UK? Being able to bring a private prosecution strengthens the distinction, a regular citizen can both sue someone for a civil offense and prosecute someone for a criminal offense. It makes it more clearly nonsense to refer to suing someone for slandering you as "prosecuting" them because you can bring prosecutions and that is not one!