Sadly so.
This is a very insightful paragraph, one that distills what I have long felt to be the correct path to redressing the systematic violation of the right to armed self-defense in California:
Much disagreement has been generated by the "open-carry" crowd. Those most interested in getting concealed carry permits considered the open-carry demonstrations to be counter-productive. The truth may turn out to be that only open carry is protected and only an open-carry suit will arrive at the proper resolution. Once open carry is protected, I believe that "shall-issue" concealed carry will follow quickly.
No doubt, the OC crowd have been jerks about it, and there is nothing to be gained politically in rubbing people's noses in their baseless fears. Yet it does represent the truest interpretation of civilian law enforcement as echoed in the combination of the Second and Third Amendments. Effectively, the three million unionized LEOs we have in this country operate to the contrary, effectively constituting the standing army internal to the US the Founders feared.
If you haven't read Balko's book on the topic, it's worth the time.
When California effectively banned open carry, I called my SO about the following problem: I live in a rural area. I wear my pistol for self-defense against coyotes, mountain lions, and wild boar. My property line goes down the center of the County road. If I walk back to my house carrying my loaded pistol on my side of said public road while still on my property, am I in violation of this law?
They got a good chuckle out of it and told me that the spirit of the law supported my interpretation.
This is how we should be educating people, not what the OC crowd was doing.
Now, to your main point...
"If carrying concealed firearms in public falls outside the Second Amendment’s scope, then nothing—not even California’s decision to restrict other, protected forms of carry—can magically endow that conduct with Second Amendment protection."
The original Constitution placed firearms regulation completely at the discretion of the States. There was to be no Federal protection for the individual preexisting right. The States would rightly have feared the Feds exerting such a preemptive power of enforcing the right against the States. It is only since the 14th Amendment that gun owners, desperate to deal with outrageous State violations of their civil liberties, sought Federal protection against their States, to which I am on record saying, 'Be careful what you wish for.' "A well regulated militia" was to be the equivalent of a State army, where the men in said militia received "regular" practice and drill under the command of the governor. Effectively, the leftist, 'that's the National Guard' does have historic merit but for its systematic exclusion of any acknowledgement of the right to self-defense as pertaining to those not so regularly engaged. But remember, said right to self-defense is not mentioned in the Constitution. Accordingly, I have felt that Natural Law competition and Federalism was a better answer in the long run than going to SCOTUS, particularly because I fear what the Feds will do pursuant to the treaty power as it is currently interpreted. I think you've considered what I've had to say about that, but if not, they're here and here.
As does mine. It's not something I've challenged. As they say, "You can beat the rap but you can't beat the ride."
Surprisingly, some of the quotes in the Peruta decision seems to indicate that the idea that the Second Amendment, unlike the First Amendment, only applied to the federal government isn't quite clear.
The Dred Scott decision is one: "It would give to persons of the negro race, ...the right to enter every other State whenever they pleased, ...to sojourn there as long as they pleased, to go where they pleased ...the full liberty of speech in public and in private upon all subjects upon which its own citizens might speak; to hold public meetings upon political affairs, and to keep and carry arms wherever they went.
There's no suggestion here that any state would be infringing the right to keep and bear arms of their citizens, though there is a suggestion that freedom of speech might be subject to state limitations.
Was it ever the case that the Fourth Amendment requirement for warrants didn't apply to the states? After all, the First Amendment explicitly states "Congress shall make no law ...", whereas the Second states, "shall not be infringed".
In all the reading of court decisions that I have done I don't recall ever reading in early decisions that persons could only keep or bear subject to state laws. But, of course, they didn't have those dreaded pistol grips that one needs in order to shoot up a school.