If that's reasonable or not really depends on what people they want to offer services to, no? No one* outside of china speaks Ehinese, while plenty of people, like me, outside of USA, UK, NZ, AU, etc. speak English.
*yes, there are for sure some people who speak mandarin, it's just not as widespread as English (or maybe Spanish)
*yes, there are for sure some people who speak mandarin, it's just not as widespread as English (or maybe Spanish)