Absolutely - I think that this is a huge problem.
Overall, of-course, this is an issue, but specific to the shotgun, a lot of folks don't realize that how any one of our unique (i.e. that weapon, with that unique serial number) may pattern can be quite different from another example of the same weapon that might well be otherwise identical.
People see/read about Federal's Flitecontrol wad without realizing that it's neither a guaranty nor cure-all. Similarly, they don't realize that their misconceptions of the shotgun "not needing to be aimed" sadly overlaps dangerously with just how the weapon will perform in real-life, particularly when they use their perceived-favorite load with that gun.
Using myself as an example, Flitecontrol is the difference between 25 yards and 40 yards being viable with buckshot, particularly with that 9th pellet being much, much less predictable. But this is on my run-of-the-mill 870...with my current lot of ammo. A different gun, a different lot, and things may -in all likelihood probably won't- be the same.
Folks -and I know that I'm preaching to the choir, here: I'm just hoping that a newbie might read this and be encouraged to do so!- need to realize that particularly for the gauge, they really need to get out there and pattern.