Actually its Ryanair who carry the risk, and so its they who should insure.
The whole thing is another advertising campaign by Ryanair - as your rights as a traveller are enshrined in law, 'not taking the option' does not allow Ryanair to legally refuse to help in accordance with the law IMO.
Like may laws, its nothing that a commercial contract term is able to vary - like putting something in a purchase agreement which allow the seller to kill the buyer without any recompense.
He just doesn't want to take out the insurance which everyone carries to cover for such an eventuality and is just whining after years of making profits by cutting back on insurance costs, the chickens now come home to roost. Just like the man who steals from the shop on the basis he'll never get caught, he now has been.