I see where you're coming from, but I don't agree. The Constitution specifically protects the people's ability to maintain the force necessary to be a credible threat. If not to maintain the threat of armed rebellion, what purpose would it serve?

Obviously actually engaging in insurrection against a constitutional government would not be constitutional. Anyone taking arms against the government would presumably believe that that government was not operating within the confines the Constitution provides; the act of insurrection would be seen by them as a remedy to an unconstitutional government and therefore neither party would be subject to it.