indeed, of course there are shades of gray in any comparative spectrum. there are more and less overtly authoritarian institutions. democracy can easily be seen as a form of authoritarianism (tyranny of the majority/plurality), albeit a much milder version than, say, military dictatorship. but any revolution that does not have as its intent an anarchistic result is not one that any anarchist i find interesting is likely to participate in - at least not with any expectation of anarchistic outcomes. as you pointed out, neither of those revolutions (fr and us) - indeed none in history that i am aware of - had anarchy as its intention. so perhaps we are speaking to different points.
edit: in terms of the institutions themselves, i am referring to generalized structures such as government, economy, religion. which apply to nation-states of all types, including monarchies, democracies, theocracies, etc.