There are many reasons why students stop schooling. This graphic below shows the reasons why students drop out of school.
Going to university is very expensive that is why students tend to work part-time to pay the tuition fees and miscellaneous. But when they find working is better than studying so they choose to stop schooling.
Another reason maybe is that the standard of education is too high. The students cannot maintain the required ratings and that is why some are disqualified to study further.
Since going to university is expensive many students prefer to study at home which is very good. Studying at home is a very good alternative in pursuing their dreamed career.