Why did the quota movement go so far?

The curfew was imposed in view of the unexpected violence, conflict and sedition situation that emerged around the general students' quota reform movement. In that case, there must be a discussion about some issues. Along with that two very relevant and urgent questions need to be answered. First, whether the demand for quota reform is logical and fair? Second, why and how did an apolitical student movement become so violent and who is to blame?