You can shoot bird shot, buck, and slugs what more do you need
Umm... How about the ability to defend yourself outside of your home?
My one and only gun for a while was a defensive pistol. A Sig 228. No, I couldn't drop a bird with it, but personally I'm much more concerned with my ability to stop someone attacking me than my ability to get food by hunting.
I want to see someone concealing a 18" shotgun in shorts and a t-shirt. Not gona happen. But you can rest assured that I can do that with my pistol. And one more thing that gives an edge to the pistol: its easier to
hide. Little things like this are important for those still living with roommates or in apartments (and those without CCW permits). Walk out the door with a long gun case and everyone knows that you've got a shotgun/rifle. Walk out with a backpack or a laptop case and no one has a clue.
mnrivrat: I think the needs are changing. When the west was being settled, someone could walk outside with a long gun and the most they'd probably get asked would be "good afternoon, sir. Going hunting?" Try that in a city today. While it is probably still legal, there is a very good chance that you're at least going to get hassled by LEOs. When your neighbor is likely to call the cops on you, discretion becomes a necessity.
My other guns right now are two combat style rifles, and hopefully another combat type pistol soon. No shotgun in sight. I do have access to one through friends and family should I go hunting or trap shooting, but I don't have any immediate need for one in my personal collection. To say it is the ONLY gun that anyone needs is a bit presumptuous. Especially on a board full of gun collectors/shooters.