When contractors get killed abroad in combat actions it draws little attention. The general public is less sympathetic to the death of a soldier that fights as a mercenary for a pay check. Regular Russian soldiers killed in foreign countries draw attention to operations the government does not care for the public to know about. This places Wagner contractors at significant risk. Contractors are somewhat anonymous and can be used for more hazardous missions.
According to Mark Galeotti, senior researcher at the Institute of International Relations in Prague,
The Russian people are not very enthused by the idea of an empire that would involve their boys coming home in body bags. Theres clearly a lack enthusiasm for this conflict. By having this military company Wagner, they can have a force they can actually deploy ... but when people die, it doesnt have to be announced. (news.com.au, 2017