You are spot on about the cargo cultism. Ever since the first great PISA-scores, we've been getting hoards of visitors from all over the world, trying to understand what makes our system good.
The problem is, even our own politicians aren't really able to comprehend the reasons. Most politicians aren't able to look at the Finnish system in a way that would question their own political views, so all the statements concerning what makes the Finnish system good are just the same old talking points, with cherry picked details from our system to fit them.
There was a big outrage in the press since in my country (Uruguay) we were at the bottom of the pack, after the governing party had made a lot of propaganda about they were doing things right this time around, doubled education spending and all that - they point out that Finland spends 6% of its PBI on education. Uruguay only recently reached that amount.
I expect that my country's politicians were amongst those that visited Finland (which, along with New Zealand, is one of our favourite references as a small and prosperous country), and that your assesment about their being unwilling to question their political views is probably right.
Here's a blog (in Spanish) that writes about what Uruguayans think the Finnish did right:
"One of the highlights is that schools offer more than education. They are centers that provide food, medical and dental care, psychological care, among other services. And last but not least, they are free. "
"Asked the key to success, Tunturi did not hesitate to answer: "The educator is highly appreciated by society. Young people see it as a profession with a future. "Statistics show that 10% of the top high school students choose this route. Grünberg said this is a feature shared by other high quality educational systems, including South Korea, where teaching attracts 5% of the top high school graduates. "In other countries would be brain surgeons or lawyers, but they are teachers or teachers in Finland," said the rector."
The problem is, even our own politicians aren't really able to comprehend the reasons. Most politicians aren't able to look at the Finnish system in a way that would question their own political views, so all the statements concerning what makes the Finnish system good are just the same old talking points, with cherry picked details from our system to fit them.