Universities in eastern bloc were really elite places. Only low single digits percent of people were able to enroll. Also majority of degrees were in STEM, education or medicine as they were deemed useful for the state. To get degree outside of STEM, political background of your family was checked and things like having family member (even say uncle) who emigrated outside of country or having grandparents who owned businesses or farm decades ago will get you discarded. So the smart kids usually have very limited path forward, so STEM it was (if you were lucky)