Why are they offering such a generous plan?

In explaining why Germany made this move, Dorothee Stapelfeldt, a Hamburg senator, called tuition fees "unjust" and added that "they discourage young people who do not have a traditional academic family background from taking up study. It is a core task of politics to ensure that young women and men can study with a high quality standard free of charge in Germany."

Also...

By educating people in Germany, they'll be more inclined to do business with Germany. It's a win-win.