All massive companies are run using debt. Why wouldn't they? The risk is somebody else's then. That has nothing to do with how financially stable they are. Moody's still suggests that they are in a good position;
King Power is considered to be very stable (Moody's Investors Service), indicating a strong financial position with minimal risk of significant changes in the near future; their main source of revenue, the duty-free business, benefits from its close ties to the Thai government, acting as a largely government-sanctioned monopoly.
Moody's has affirmed King Power Capital's credit rating with a stable outlook, signifying confidence in their financial health.