Although the proliferation of Massive Open Online Courses (MOOCs) has created highly interactive learning environment for higher education, the low completion rate (or high dropout rate) deteriorates the development of MOOC courses. This study explores why learners are not highly engaged in MOOCs from the perspective of academic hardiness and learning engagement. The interplay of online academic hardiness and online learning engagement is mapped through both structural equation model and predictive model. Our explanatory and predictive analysis found that commitment is the most important factor of online academic hardiness, significantly influencing learning engagement. Moreover, the role of challenge contributes much to cognitive and emotional engagement. Other interesting findings and instructional implication will be discussed in the paper.