Quiet quitting—meeting formal role requirements while withholding discretionary effort—has sparked a central debate: is it primarily a manifestation of organizational shortcomings or an individual coping strategy? We test these competing accounts using a dual-path structural equation model on cross-sectional data from 600 employees across multiple sectors in Lebanon. The model exhibited acceptable fit (χ²/df = 2.48; CFI = 0.943; RMSEA = 0.059). Results indicate that intrinsic motivation is the strongest negative predictor of quiet quitting, whereas HRM system gaps are associated with quiet quitting primarily through burnout (partial mediation). Direct effects of HRM gaps are weaker but non-trivial, suggesting that quiet quitting reflects both an individual coping response and a reaction to organizational shortcomings. This study provides the first integrated, head-to-head test of HRM system gaps versus intrinsic motivation, extends evidence beyond over-represented contexts through a multi-sector Lebanese sample, and delineates where managerial interventions—bolstering intrinsic motivation and mitigating burnout through support and voice—are likely to yield the greatest marginal returns.