Well, first off its just a thing. A 30 year old truck sitting on a farm is nothing to call your father "worthless" over. Even if he had called you, wouldn't have changed the fact that the truck was all shot up.
Personally I don't see the draw in shooting up a perfectly good vehicle, some real stupidity involved here. If for no other reason than you're making a mess out of your property and your belongings. I think your brother needs to make this right. You can't just get drunk, call your friends over and start shooting things; adults take responsibility for these sorts of things.
Smells like a lack of respect and a lack of pride in one's property. Just my .02, need to have a sit-down with that brother of yours.