Discrimination???

In Spain, every time the private schools renew the agreement to receive finantial help from the state, some media launch the following claim: there are some schools that discriminate girls because only boys are allowed to study there, and the same happens with some schools only for girls. And those schools receive money from the state, so this is a scandal, according those newspapers.
But I think: nobody constrains families to bring their kids to any kind of school, so if they chose a school only for boys or only for girls, they are free and there is no discrimination but choice, in my opinion.