Private Universities in Germany were the first to offer courses in English. Even when public universities only offered Masters and doctorates in English, the private universities had long been offering Bachelor courses in English.
This simple fact has definitely made private universities more popular to anglophone foreigners than public universities. However, today with the many applicants being spoiled for choice, with public universities also offering Bachelor courses in English, then we have to compare the cost of both.
Although the cost of private universities in Germany is a bit restrictive, when compared to the US and the UK, it still remains quite low. This could explain the increase in the number of students picking private universities over public ones.
Most prominent Kenyans have also learnt of this secret and many are sending their children to private German universities.