RE: buck shot
It doesn't carry as far as a slug would if you missed, so in more populated areas it might be considered safer.
You also get a spread to it, so you wouldn't need to aim as accurately I guess. Probably people doing drives where they would shoot at running deer at closer ranges would like it.
I personally don't like Buck Shot and have never used it. I see where it has a purpose, but most use it outside of what I would consider it's effective range, or they use it because they don't want to invest the time and effort to get a slug to shoot accurately. Or they just want to blast at anything that comes running by.
If that is the way someone else wants to hunt that's fine I guess. It is not the way I want to hunt though so I don't see much need for it. Maybe if I was shooting in a real populated area and I had to use it I would. But then I would probably use my bow if my shots had to be that close.
Paul