Why was Duck Hunt Duo included in Smash Bros?

Also in a Famitsu interview, Super Smash Bros. for Wii U director Masahiro Sakurai talked about the inclusion of Duck Hunt.

Sakurai feels that the original NES title, which worked with the NES Zapper light-gun, is "a quite major game." He was keen to revive the setting of the original release in the new Super Smash Bros. games, and that it's "very important how different characters make the game interesting with their individuality."

The Duck Hunt Duo mechanic is something that Sakurai wanted to implement, as well, with a third person who attacks.

Also in the report, Sakurai revealed that Super Smash Bros. Melee could have gotten eight player support.

What do you think of the inclusion of Dunk Hunt Dog in the new games?