I worded it awkwardly.
Casual gamers usually make up the majority of a community, and Smash is definitely no exception. In fact, this probably applies to us more than it does other communities for different fighters.
So, besides money steering the course for a game, what other possible outcomes are there that are not directly detrimental? "For fun" probably goes hand in hand with money and making it more accessible to a larger, less-skilled group of players, or you can make it competitive, which ensures quality, but not necessarily sales.
The hardcore and casual demographics may be split, but I don't see Nintendo's reasoning behind making Brawl a watered-down version of Melee, aside from serious sales coming in for a new console.
If a game is good, usually that's enough motive for casual or hardcore gamers to try it out. Melee might've been harder, but with enough time, dedication, and effort, you'll get better, and that also works for a universal number of activities.
I'm going off in tangents here, but Brawl had the potential to be really good, and look at how large a community of 10 years has gotten, and an extremely high learning curve game have gone.
*Edit* I'm also unfamiliar with Dragon Quest. Was their development geared towards a good quality game?