I think one thing to bear in mind, is that the competitive scene is really when a critical mass of players is reached. Then there are enough in the community to form up regular groups/clans and play competitively.
You cannot appeal to a "competitive" community, until your casual community is at it's peak and there is a big enough player pool to move into it.
How many people started playing a game because of the competitive side of it? Very very few players. Most players start a game, because the games are fun or their friends/reviews recommend it to them.
I played CS and Supcom competitively and started both as a casual gamer.
That said, I do think that the game should listen to the competitive players a little more in terms of balance, as normally games that are balanced at high level are balanced for the low level too. The problem at the moment in this game, is that there are no top players, the game is 100% casual pretty much at the mo, there is no way to play competitvely due to the stats and matchmaking.
A change like Pre-Made matchmaking and stat tracking should be very high up on the list, it serves both groups. A big problem for new casual players is getting stomped by pre-mades and seen as most competitive players will be in premades, I am sure they will be happier if they can matchmake properly.
At the moment though, Demigod doesn't need a strong competitive focus, it needs a strong infrastructure for casual players, if they keep attracting more players, the competition will evolve from that.
The comments on SC2 are interesting. I wonder if they will listen too much to the competitive scene, the game looks nothing more than a graphical update of the original, no groundbreaking features, which the rest of the RTS world has moved into (realtime physics projectiles, cover systems, strategic zoom out).