Why is gambling with citizens health and encouraging predatory and extortionist behavior by hospitals and insurance conglomerates on people who are sick and vulnerable an obvious states issue, while stuff like 'right to have guns in your house' is a federal law.
Well, because the latter was specifically in the constitution, and is key to our ability to protect ourselves from tyranny. The former was not in the constitution. If you don't like it you can feel free to amend the constitution. It's been done, and it will be done again.
Funny, I actually made that point once (when I was feeling particularly sarcastic). It was rather derogatory and went something like this "Hmm interesting... all these people in West Virginia seem to hate voting for better healthcare and love voting to get more guns, so maybe their answer to healthcare problem is rational after all and it is to just put those guns to good use".