He reined over a period of drought, but there’s no way he could have controlled the weather. That’s like blaming the government for there being car accidents. Simba exploited the working and noble classes into thinking that Scar was to blame for natural cycles. Thus he was able to lead a rebellion against their best interests and restored his line to the monarchy. Upper nobles playing everyone else against each other but, at the end of the day, the monarchical status quo was maintained. Feudalism in action.