Why is Snake in Super Smash Brothers Brawl?

Answer 1

the creator of Solid Snake wanted to put him in Melee, but it was too far in development, but Sakurai agreed to put him in Brawl

Answer 2

Because the creators decided that he should be in the game. He is slow, but his attacks are very high.

Answer 3

The Super Smash Bros. series is basically a Nintendo all-stars fighting game series, and because Sonic is a Nintendo character, Nintendo gave Sonic a place in SSBB