Popularity does not automatically equal practicality and applicability...in fact it often equals the opposite.
Lot's folks buy it because it's a novelty. IMHO, anyone that thinks .410 is a viable self defense round is very misinformed...might be good in a pinch, but why choose a less than optimal round when far better alternatives are available for the same money and quality of manufacture?
http://www.theboxotruth.com/docs/bot41.htm
Well I have seen what 5 .32 cal sized slugs from the 3" 000 buck magnum handgun loads does to an OKC phone book at 25 feet and that was just one pull of the trigger. Five pulls of the trigger did more damage to that book than 15 rounds of 9mm sd ever could. I guess I can say that I would not want to go up against somebody in a room in my house when they have the Judge 3" mag loaded with 410 000 buck handgun loads and I only have my 9mm.