Well, in my humble opinion, for many foreigners whose native languages are quite different from the Chinese language, learning the Chinese language means undergoing a totally new learning experience. It’s like going on a journey where what they have learnt in their native languages or other foreign languages could not help them very much.
I mean, compared with alphabet letters, it needs a longer time to learn how to write Chinese characters. Since there are lots of Chinese characters sharing a pronunciation, for instance, 鹿, which means deer, 路, which means road, 露, which means dew, sharing the same pronunication lù, writing Pinyin alone could not express exactly what people want to say.
So, it’s necessary to learn lots of things which seem quite difficult to them, when they start to learn Chinese, for instance, strokes, stroke orders, Chinese character structures, pronunciations and tones. And this is not an easy task for many foreigners. Please come to think about it, even native speakers of the Chinese language need to spend years of learning Chinese.
And it needs patience and stamina to plough through this learning process. And for foreigners who want to learn Chinese in a much quicker way, they might feel frustrated and perhaps they might later drop learning the Chinese language, after realizing that it would take a longer time to be able to understand this language.
Of course, once foreigners decide to continue to learn this language, then after a long period of dedicated learning, they could find that the Chinese language is not that hard as it seems to be. So, once they surmount difficulties that they meet at the early phase of learning Chinese, their hard works and efforts will pay off.