The 9th & 10th are still linked & valid. You are right about the purpose of the 9th, but it wasn't working after the civil war. Thus, the 14th was necessary to defend even the 2nd, among the others.
Read the ratification debates from 1868. Lots of good points defending gun rights, which were being violated by states.
For a politician or bureaucrat of that time having just witnessed the civil war wherein the citizens took up arms against one another and one side against the government, no doubt they were concerned. Visions in their head of, "but what if they ever join forces against the government (state of federal) and we can't pit one against the other? Damn, we better work to diminish the Second Amendment."
In the war of two worlds between the value creators and value destroyers I think the value destroyers prefer a gun war over a cyberspace/communication/information war. That is, they probably think they have more ammunition in pitting the military against the people where they have a greater chance of winning by brute force as opposed to not having a snowballs chance in hell of winning in fair/unbiased debate forums. This is an opportunity for a biased mainstream media to redeem itself.