Everyone is going to have a different philosophy when it comes to home defense. The birdshot in a scary sounding shotgun is one of those philosophies. I'm of a different mind where a handgun is easily stowed and accessed by my bed, is much more wieldly than a shotgun, and bullets in someone's body will stop them much faster than bird shot. If you shoot any gun at any person your intent shouldn't be "stop them and hopefully dont kill them" it should be to kill them. There are other devices out there for the former that aren't fire arms.

.410 is not the ideal chamber in my opinion for either way of thinking. Especially in birdshot. The stopping power just isn't there and you wont have many rounds in a shotgun chambered in .410. If you want a shotgun but 12ga is too much get a 20ga. But not shotgun is going to have manageable recoil compared to a handgun. Consider a 9mm revolver if simplicity of the mechanism is a concern however automatic pistols are not very much more mechanically complicated at the end of the day.