The liability for Disney is tremendous.
If someone sneaks a gun or bomb into one of their parks and kills visitors, not only would they be sued for millions, they would also lose millions more in revenue from people avoiding their parks. Yes, they search you going in.
As for the smoking...the anti-tobacco crowd is very vocal and lawsuit happy. Imagine some kid having an asthma attack after being exposed to someone smoking in the park.
This is all about limiting liability.
Thinking the insurance industry can be found at the source of much today. I suppose we’d have to include the justice system as well.