Not just alcohol causes impairment. Over the counter drugs. Motorcyclists more susceptible to injury or death if riding impaired. Why more deaths for impaired motorcyclists. Less likely to wear protective gear.
Motorcycles require more complex skills to operate.
2,400 tasks involved in riding a motorcycle. 600 tasks involved in driving a car. Intoxicated is a legal definition. Impairment begins long before intoxication. Crucial skills which can become affected by as little as one drink.