No, it's not different cultures

Blaming "different cultures" is too easy and answer—what does 'culture' mean? Different holidays? Habits? History? Culture is too general a term to be useful.

But you ask, "Are not cultural things like gift-giving, eating together and passing business cards important?" Yes, but ... mostly no. I grin every time I watch Westerners practice the Chinese way of passing and receiving business cards at the same time. The Westerners will never get it right ... and most Chinese don't care. 

Having good cultural manners is important, but poor manners are rarely the root cause of business relationship problems.

Try again ...