i imagine they were hired because they can speak English so they don't need to speak Chinese to do their job. So learning Chinese is up to them and if they feel like it more than a need to learn it. There is a decent amount of English in china so a non Chinese speaking person can get by fine without it.

对不起。。。。。因为汉语很难，还有很多中国人会说一点 英语 。。对不对？

Because Chinese is too difficulty to them

Many foreigners who can speak Chinese very good living in China as well.

因为汉语很难，还有很多中国人会说一点普通话。。对不对？