I can understand that you think more is better and in some cases I'll agree with you.
But with one you have to take the other.
What good is an ounce of lead at close range if the targeted threat isn't hit?
The user needs to learn how their scattergun will act no matter the gauge.
Also keep in mind that others in a family unit need to learn how to use the same HD weapon as the man of the house,and which would be easier to handle for a child a 12 gauge or a .410,what about an elderly family member,or the lady of the house that might not be thrilled about getting knocked around?