Mario Party destroys relationships; Smash Brothers re-bonds them.
How did we get to smashboards :I But nobody/few bought 64 to play competitively, it all started casual and it did fine, thus getting the "All mighty perfection that is Melee" /sarcasm
First off, there were small (what we now call smashfests) "get together's" of people who thought there were good, as well as actual tournaments. The tournament scene for Smash 64 has never been huge (at least offline), but it has existed since the launch of the game
Also, over 3 million copies of Smash 64 were sold, and it was a surprise success, which is why Melee was made as a (then) launch title for the GameCube with a huge budget (for the time).
Oh, and Sakurai does consider Melee the best entry in the franchise thus far and the most boundary pushing game as well fyi.
While I'm at it, the fact that hundreds of thousands of people tuned in to watch the finals of a 12 year old game is a testament to Melee and Melee's development staffs' success, as well as the appreciation of the game as a competitive, enjoyable, and entertaining game to both play and watch.
I mean, how many 12 year old CONSOLE games would even 1,000 people watch on a livestream=???