Top 7. Because there is culture difference.
One of the main reasons Chinese is so difficult for westerners is that the culture between the East and the West has been isolated for so long. China has had extensive contact with the West in the last few decades, but there is still a vast sea of knowledge and ideas that is not shared by both cultures. When westerners and Chinese get together, there is often not just a language barrier, but an immense cultural barrier as well.

原因七：存在文化差异。
东方、西方相互之间文化分隔的时间太长，这也是汉语对于西方人来说为何那么难学的主要原因。尽管在过去几十年里中国和西方之间有了广泛的接触，然而，中国人的知识和思想浩瀚如海，西方人却无缘享用。即使有朝一日西方人想和中国人融合成一体，其障碍往往也并非只是语言一个方面而已，最大的障碍是巨大的文化差异。