Militaries were not sent against anyone, they were placed to protect more of the institutions (that were not on the paths of protests), so that police forces could be relieved there to be concentrated on hot protest areas.
The Gendarmerie (a quasi-military force) have been quite apt at sending hard things into people's faces, no need to send in the military. This was purely a show of force from Macron.
The Gendarmerie has a double status: it's a military force but it's mission is one of police.
Now, a state (democratic or not) _has to_ show force, because that's one of the definitions of a state: an entity that takes the monopoly on violence.
Given the violence that demonstrated itself in some very specific places by very specific groups of people (and disrupted things even worse for others), it has to be expected that the state reacts. The contrary would be a sign of weakness through which more chaos would pour.
