They key to using buckshot- and any other hunting tool- is understanding what you're using and using it appropriately.
Pattern your load, and respect the distance limitations. Guys that say they have a 100 yard buckshot shotgun are not respecting the limitations. Even IF they have a good pattern at that distance.
Use it appropriately. My gun will keep 6 00 pellets in 12" at 40 yards. That's deadly on a deer. At 50 yards it's not so great. So I know if I ever go I'll have to limit myself to 40 yard shots. Some guns may be limited to 30 yards, or 20. You don't know until you shoot it and see what your load is doing.
Another thing is that patterns can fall apart quickly. You have to pattern your gun at different distances. A nice pattern at 15 yards does not mean you're good to go. As it can be all over the place at 30.
People are BAD at range estimation. Which is probably where allot of the bad shots come to play. That is not the fault of the buckshot. That's the user.
Just like archery, pistol, spear, and rifle hunting... You need to know what you're using, how to use it, and what the limitations are.
-Jake