The 'expansionistic, imperialistic Napoleon' is Napoleon as his enemies want him to be seen. Since those enemies included the British, this is largely how Napoleon is perceived in the English-speaking world.

The French perception of Napoleon is more benevolent: a liberaliser who reformed the law and French society, and someone who took on the conservative monarchies of Europe. The French Revolution and its values remain a key part of French culture, and these values are associated with Napoleon.

I would also dispute that France is a particularly non-militaristic society. It's a nuclear power with a large military capability, and has a visible paramilitary police force (the gendarmerie). Bastille Day celebrations are militaristic in some respects, and a lot of apparent post-war French 'non-militarism' is actually rejection of American foreign policy, rather than a rejection of militarism.