We seem to have drifted a long way from the OP. The .410 shotgun is more than adequate for shooters who want a light shotgun that won't beat them to death with recoil. I see it in the same category as a .357Mag lever-action rifle. Are either longarm as powerful as a 12ga./.308Win longarm?....no. But they do the job adequately.
The military/LEO choices are a red herring. Just because the military tends to defend its "property" with grenades and .50BMG machine guns doesn't make them a good choice for civilian HD. Conversely, LEO's often resopnd to situations first with handguns....then with SWAT teams. Shotguns don't see much use anymore.
For an inexperienced shooter looking for a good HD/recreational shotgun, the .410 has a lot to offer. As they gain more experience and/or look toward more sporting uses (wingshooting, 3-Gun, trap), the 12ga becomes a better choice. Choose the right tool for the job....and for the user.
Proud member of Gun Culture 2.0......