I know the purpose my SBS serves, and what I teach my students to do with it.
In my experience, the gunfight is what it is going to be......not what you want it to be, or what you equipped yourself for.
If you can equip your SBS, for a very reasonable fee, with a set of rugged iron sights that will enable you to engage from point-blank to 100yds, why not do so? Why limit your effectiveness to conversation distances only?
One of the main features of the shotgun that has kept it so popular is its ability to employ a wide array of ammunition. They are devastating in close quarters, but they can be accurately utilized at further distances if properly equipped.
I was toting a Remington 870 in my first gunfight and have had a soft spot for them every since. Granted, it was a 20" USMC-issue Rem870, but it had rifle sights and I knew how to use them.