That's not always the case.
We live in a school district that provided a terrific education for our children from grade school all the way to high school.
It all depends on the goals and attitudes of the district and individual school administrators. Either they care about the kids' education or they don't.
I fully expected that type of response, or one along the lines of ‘my wife’s a teacher, cares about her kids etc etc.’
I too attended a district that was constantly held up as a paragon of public ed. But upon my arrival at a highly competitive university that drew blue chip students from a dozen cities I quickly realized how woefully unprepared I was compared to my peers and/or the demands of my studies.
Respectfully, I also think that an attribution error is possible in this discussion. Your kids are motivated, well behaved, etc and probably could have succeeded in any school because of the near constant learning that takes place exclusive of the classroom and school year.
Anecdotes may be true/accurate but they cannot overcome the abysmal performance and built in biases of public union dominated schools, to say nothing of their shocking return on mountains of cash.