Determination of players? Everyone is spoiled with netplay already 
. I personally am going to travel and participate in tournaments but some people just won't/can't because of distance or financial reasons. I hope some people will still take this game seriously.
Well, determination of players and accessibility, obviously. I think a PS2 is far more accessible than PC because of portability and easy setup (important factors for a tourney). If people are willing to be serious for a game at the very least they should try to hold offline meets with locals (which I've done for IaMP, even though it's a 95% netplay-based game in the US). If they're unable to do that or travel to a tourney where the game has a presence then clearly they're not serious enough.
Which in itself is a bit of a problem. There will always be scrub casual /jp/ players, but the real scene is dying. When MBAC came out, the scene was still growing, and now it's tanking. People forgot about every WT after 10, AM doesn't actually have Melty, FR doesn't have Melty, etc. There are a handful of new people, but the only one I've seen willing to travel for the game is Masu.
WT died not because of the players but because Arlieth stopped running tournaments. You also have to keep in mind that even when Arlieth popularized the game (and he tried hard and did a great job; he got a lot of FFA people into it and the entire MB community here is because of him) it was already an old game.
AM was a Melty tourney for like one event, and that event was when it was me taking over for someone else. You have to keep in mind that I have an obvious predilection against MBAC and didn't really have a lot of motivation to keep the hype rolling once AM became "bell's event".
I think people took a while to realize that MBAC was, on many levels, not a very good game. Combine that with a very small scene full of many casual players who were in it only because of Tsukihime and had no real competitive drive and the scene was going to thin itself out over time, which led to a snowball effect: people don't want to play a game with a small scene, which led to people quitting, etc. Combine that with the real driving force behind the scene disappearing and you have what is happening now.
To be fair, Melty's scene isn't even as dead as it was when the game first started out. MBAC gets a lot of play by many people. Most of them probably don't matter, true, but the game isn't dead until you have absolutely nobody playing it, which is more than likely what will happen once MBAA becomes fully accessible. Many of the hardcore players are waiting for the definitive version that is accessible to them as well as a driving force in the community to jumpstart things. Neither of these is available now which is why the scene is stagnating.
