Other lower courts have found that the 2nd is incorporated under the 14th (i.e. states can't restrict more than the feds) so the Supreme Court will end up deciding the issue sooner or later.

The opinion is annoying for how standard it is - cherry picking all the way down. It cites varying state laws about self defense as evidence that the states get to do their own thing. Supreme Court decisions do this all the time; just last year the majority cited the fact that of all states that allow the death penalty very few explicitly allow it to be applied to minors but then bizarrely used that as a reason to end the "legal laboratory" of states. Heller which upheld the 2nd as an individual right also held that fully automatic guns weren't covered because there are so few legal machine guns in circulation -- no shit sherlock, they have been heavily regulated since 1968 and the sale of new ones banned since 1986 (due to restricted supply the going rate for a legal M16 is $15k).

The Federal courts wouldn't need to do all this legal squinting and cherry picking but for the fact that ever since the New Deal the national courts have had a plenary power to make law and set national policy. It is no longer possible for a Federal court to look at a case and say "not my job." In Gonzales v Raich a woman who was growing medical marijuana in her backyard, for her own consumption, and with a license from California was found guilty under Federal law because by not participating in interstate commerce she was ... wait for it ... participating in interstate commerce by not buying from someone else and therefore altering the general price. That conclusion was allowed because a New Deal court wanted to uphold price fixing measures on wheat used the same logic. Oh, and if you think it was the left side of the bench that dissented, you'd be dead wrong. Justice Thomas:

If the Federal Government can regulate growing a half-dozen cannabis plants for personal consumption (not because it is interstate commerce, but because it is inextricably bound up with interstate commerce), then Congress' Article I powers -- as expanded by the Necessary and Proper Clause -- have no meaningful limits.

* McCain, Bush, and many others from the first two branches signed Campaign Finance Reform despite the fact that they thought it was unconstitutional. Remember all the politicians who lost the next election based on the fact that they violated their oath of office? Me neither.