I think the cultural thing is actually the reverse: Westerners including Anglo-Americans usually don't want to discuss money because they see it as a proxy for social hierarchies they profess disbelief in and orthogonal to self-worth.
On the other hand, in countries like India where salary is usually the third thing a complete stranger asks you about have a strong sense of social hierarchy and see frank discussion of income differences as an important part of establishing where they sit in it (and their potential for moving up). Meanwhile, I wasn't even mildly curious about how much they earned relative to me and their peers because it wasn't going to affect my perception of the conversation in the slightest, but was a little embarrassed that I could afford to spend months travelling in their country without having to do much to earn the privilege and a salary I'd been unhappy with was usually a large multiple of theirs.
I always viewed the "that decision was made above my paygrade" as mildly sarcastic in its implications.
On the other hand, in countries like India where salary is usually the third thing a complete stranger asks you about have a strong sense of social hierarchy and see frank discussion of income differences as an important part of establishing where they sit in it (and their potential for moving up). Meanwhile, I wasn't even mildly curious about how much they earned relative to me and their peers because it wasn't going to affect my perception of the conversation in the slightest, but was a little embarrassed that I could afford to spend months travelling in their country without having to do much to earn the privilege and a salary I'd been unhappy with was usually a large multiple of theirs.
I always viewed the "that decision was made above my paygrade" as mildly sarcastic in its implications.