Bullshit. Nobody ever wants to talk with another human being and line up to touch kiosks. You contact far more pathogens by touching public handrails and doorknobs.
If this is a real problem (of which I'm doubtful) McDonalds, being one of the most responsive large companies in the world, will fix it first by adding to human janitorial duties and soon after have the kiosk self clean, or remove it and push everyone to the my McD app on their own, filthy phone