If someone attempts to cut through the bolt, that hardened pin won’t cut with a standard blade. But there’s plenty of carbide blades that will, so the pin spins around & bounces back & forth to make cutting very difficult. If the thief is successful in cutting it, he deserves to get in. No, not really. The point is to slow him down so he’ll give up. The only times I’ve ever seen bolts cut is by maintenance personnel. Thieves will kick the door over & over, use a crowbar, but sawing the bolt… no. The weakest part of a deadbolt installation is the wood around the lock & the jamb where the strike is. If those aren’t beefed up with reinforcements, a couple stiff kicks could well burst the door open. Best would be a metal door & frame, next would be a reinforcing skin around the lock side of the door & a large strike plate with 3 to 4 inch screws.