Ask long termers how many trusted chinese friends they have, very few, if any. The chinese have their in and out circles, ignore that at your own peril.

That's sounds more like a personal issue than a cultural trait.

Most of the long-termers I know have plenty of trusted Chinese friends. I know I do. Never tried to cheat me once. And I know some of them have had the opportunity.

Now trusting 100% of people as you claim you did? That is not wise. But perhaps you were still young and naive.