Fields with default values are not saved anymore

When I declare a default value for a field in the field declaration, I expect that this value is returned, if the editor has not changed it. In Jahia 5 this field is only saved once the editor clicked on the field group displaying this field. If (s)he never clicked on the field group, the field is not saved and the template will display null instead of the default value.

Is that a bug or a feature? In Jahia 4.x it did not work like that and fields with default values were always saved, even if the editor did not click on the fields group.