1. It doesn't look stupid like a Spikes flare launcher when attached to a rifle
2. It is freakin fun to shoot
3. There are also other rounds out there. With a destructive device stamp, you can shoot anything through it. Rubber Buck, Smoke (and SAF smoke), Chalk, Flares, Wood batons, Ferret rounds, and others. You can also use the 12 gauge and 22lr adapters.
A long time ago, when I decided to get a launcher, I decided that I wanted to do it correctly and not just settle for a flare launcher. Pretty happy with my decision.