Some possibilities: maybe the European cultures (the white of which you say) have had a break-up of large family structures over the course of the last century, leading to therapy in the first place. That would fit in with some of my other comments in this thread around loneliness and a sick society. And following this it might be that some other cultures with large nuclear families have a sanity check within them where there are people to confide in and give guidance. That's what a therapist does in the end: empathize and give guidance.

Another possibility is there are cultural norms: psychotherapy originates in Europe / Central Europe where it had a blossoming in the late 19th century and spread, and became quite fashionable in among the educated classes (up to and especially in the 1960's, for example).