A shotgun on one hand is great for hunting birds and some animals, whereas it's a horrible option for self defense, especially in cities. The risk of collateral damage is simply too high, especially with buckshot, as they don't tumble and slow down after going through an object, they simply flatten slightly and keep going. A 5.56 round on the other hand, starts tumbling upon hitting anything, which slows it down drastically, and lessens the chance of an innocent bystander or neighbor being hit.

Thank you for this. I've asked numerous other people to explain why it was a bad idea and the difference between weapons and no one has responded back.