English is compulsory for all school students in China. Many will start learning English at kindergarten. By grade 3 or primary school, everyone will be taking English lessons. The high school entrance exams (Zhongkou), high school graduation exams, and university entrance exams (Gaokou) all include English as a major section of the marks. All university majors will do an English exam such as the TEM or CET exams. Many professional examinations, taken in working life, also have an English language component.
So why are there so many examples of Chinglish on signs and menus?
I think the biggest reason is, “I don’t care.” The person making the sign doesn’t really put any effort into trying to be correct. They just put the text into a dictionary or online translator and copy paste the gibbering that results.
Another reason is simply misreading. Someone composes the text correctly but the person printing the sign doesn’t know any English. They then copy it incorrectly.
English is compulsory but hasn’t been so historically. Just twenty years ago, the education system effectively didn’t teach English and so many middle aged people don’t know the language at all.
The Chinese concept of face and loosing face prevents people from asking for help. People often over estimate their abilities.