The reasons I don't like a shotgun for home defense:
You can not dirrect every pellet out of it. Sure at very close range they act like a single mass, but in my house there are open areas 60ft across.
Next, if you rack a pump (unmistakable by the way) and the perp is now afraid for their life, you are now NOT in jeopardy for your life and could possibly get crusified in court as the make my day law doesn't protect you anymore; at least that could be argued.
Lastly, I've used an AR in 9mm for years for house clearing, and trust it with my life. Those 32 rounds in a single mag help too. Mind you I don't trust a 9mm handgun with a single shot, but I don't ever plan to shoot someone with one shot. You shoot until the target no longer presents itself as a threat...which is incapacitation.

The following Officer's report would read like this,"Sir, why did you shoot the victim 32 times?" Response from shooter, "I'm the victim, he was in my house and every time a bullet hit him he would move so I would shoot again. I stopped at 32 bullets because my weapon was empty and he didn't move while I reloaded."

In all seriousness; shotguns are great for unskilled home defense, but with proper training there are better options.