People I like cite this reassuring post (see also here) concerning the California decision. Here’s the gist of the supposed reassurance:

So, generally, parents have three options for educating their kids in California: (1) public school; (2) private school; or (3) credentialed tutor. This is not as bad for homeschoolers as it looks. To be a private school in California, all the parent has to do is be "capable of teaching" the required subjects in the English language and offer instruction in the same "branches of study" required to be taught in the public schools. They also have to keep a register of enrollment at their "school" and a record of attendance. Once a year they have to file an affidavit with the State Superintendent of Public Instruction with things like their names and address, the names of the students and their addresses, a criminal background check (since we don’t want unsupervised felons teaching kids), and their attendance register. That’s it.

Here, by way of contrast, is a passage from the appellate decision:

Additionally, the Turner court rejected, and noted that courts in other states had
also rejected, the notion that parents instructing their children at home come within the private full-time day school exemption in then-section 16624 (now section 48222). The court stated that a simple reading of the statutes governing private schools and home instruction by private tutors shows the Legislature intended to distinguish the two, for if
a private school includes a parent or private tutor instructing a child at home, there would be no purpose in writing separate legislation for private instruction at home. (Turner, supra, 121 Cal.App.2d Supp. at p. 868; accord Shinn, supra, 195 Cal.App.2d at p. 693.) Moreover, even if being taught at a parent’s home could be construed as attendance at a private day school, the parents in Turner had not demonstrated that their
home already qualified as a private school under the requirements of the Education
Code. (Turner, at p. 869.)

The thrust of the argument here is that a typical homeschool is not a private school under the meaning of the law. The last sentence doesn’t really diminish the force of the opening sentences; the judges simply concede that, even if such a case could be made, these parents haven’t taken that route.

Later in the opinion, there’s this:

It is
clear that the education of the children at their home, whatever the quality of that education, does not qualify for the private full-time day school or credentialed tutor
exemptions from compulsory education in a public full-time day school.

This court hasn’t been persuaded that declaring a homeschool a private school makes it so. This court, by the way, also regards enrollment in an independent study program under the aegis of a private school as a "ruse":

Section 48222
provides an exemption from compulsory public school education for “[c]hildren who
are being instructed in a private full-time day school.” (Italics added.) It is the
language of the statutes that constitutes California’s plan for education of its children. Thus, under California’s compulsory public school education law, Mr. Neven’s occasional observation of mother’s instruction of the children and their occasional taking of tests at the private school is without legal significance.

If you look at two other cases cited here, you get a similar picture. Here’s People v. Turner, a 1953 case:

We likewise fail to find any merit in defendants’ claim that they come within the classification of a "private school" within the meaning of section 16624 and hence are exempted from the operation of the statute. The contrary was held in State v. Counort (1912), 69 Wash. 361 [124 P. 910, 911, 41 L.R.A.N.S. 95]; State v. Will (1916), 99 Kan. 167 [160 P. 1023]; State v. Hoyt, supra. [12] Moreover, a mere reading of sections 16624 and 16625 clearly indicates that the Legislature intended to distinguish between private schools, upon the one hand, and home instruction by a private tutor or other person, on the other. If a "private school" as that term is used in section 16624 necessarily comprehends a parent or private tutor instructing at home, there was no necessity to make specific provision exempting the latter.

And here’s In re Shinn, a 1961 case involving a family’s attempt to educate at home children they regarded as exceptional:

Home education, regardless of its worth, is not the legal equivalent of attendance in school in the absence of instruction by qualified private tutors.

To be sure, these cases are old, and what the parents were attempting at that time was, in a sense, extraordinary. But those two courts, along with the current appellate court, offer a very straightforward reading of the California statute, which (unfortunately for homeschoolers) hasn’t been amended. Perhaps state and local education administrators can be "creative" in their interpretation of the law, but they’re doing so against the clear reading offered by the courts. But there have been times, as I’ve noted in another post, that the state has been less willing to be creative. Do homeschoolers want to rely on the "grace" of the bureaucracy? Better, I think, to change the law, making explicit provision for homeschooling. That’s harder than persuading administrators or judges, but more consonant with the spirit of democratic republicanism, as it was articulated and practiced by the Founders.