If you have 46 shotguns you don't NEED a dedicated specifically configured Home Defense shotgun.
However, if you have 46 shotguns then certainly some of those shotguns are specifically configured for particular tasks. You might have a lightweight field gun to carry in the field on a hunt. You might have a heavy over under specifically intended for clay games where you carry the gun very little, but fire hundreds of shells at an outing. You probably have several guns that you have an emotional connection with, these could be guns passed down through your family, or guns that you intend on passing down. These reasons for particular gun configurations are valid reasons to own particular guns.
There are those among us, myself included, that also choose to have a shotgun specifically configured for home defense. In my case it is an 870 with a short (18 1/2") barrel and an extended magazine tube that matches the overall length of the barrel. I have added weight in the buttstock to improve the balance and just plain make the gun heavier for the stout buckshot loads. My gun also has a light on the foreend for use in any condition day or night. In my case the gun is locked in a way that prevents access to the trigger so I am comfortable leaving it fully loaded with 1 in the chamber and 6 in the magazine tube. Additionally I have 5 more shells affixed to the exterior of the shotgun.
The gun stays locked in the same place all the time. I have rapid access to the firearm, and always know where it is, and how it is loaded, it is secure and safe from children, houseguests, and even a potential bad guy.
Would a more traditionally configured 870 work just as well, something with a standard magazine and 28" barrel? Sure it would, but it might not be loaded and ready for quick access. Do I plan on needing all of those extra shells? No, I don't think I would ever need that many shells, but what if I did. Having them in or on the gun is no bother for me, and if I ever did need them I certainly don't want to stop and look in the cabinet for them.
It is all about choices. I have chosen to be able to protect myself and my family in a certain way. Others choose to protect themselves in other ways. Many don't choose to protect themselves at all. We live in a country that allows us all the freedom to choose. Your choice is your business, and I support your choice, whatever it might be.