Notes about WTA and draws:
I. The rules of diplomacy state (if I remember correctly) that if one player controls 18 supply centers, they win. If the players still in the game unanimously agree, then the game can also end in a draw, which is divided equally among them.
Thus, there are 8 different endings for a country, preferable in this order:
1. Victory
2. 2-country draw
3. 3-country draw
4. 4-country draw
5. 5-country draw
6. 6-country draw
7. 7-country draw
8. Elimination from the game/survival in a won game
As such, any victory conditions that attempt to accurately represent the rules of Diplomacy must never reward players in such a way so that this ranking does not hold.
II. It is not at all obvious that an optimal game of Diplomacy will result in a draw. As a game of imperfect information, Diplomacy inevitably involves some luck; saying that a perfect game of Diplomacy will result in a draw is like saying that a perfect game of Hold 'Em will result in every player having the same-sized stack as when the game began. If, under the current WTA rules, a player believes that they have greater than a 1/3 chance of achieving victory if they abandon any chance of a draw, it is in their best interest to strive for victory. (And this even assumes that if their attempt fails, they will lose - in many cases, a failed attempt at victory will simply result in participation in that same draw.)
III. Making decisions based on theoretical forum-Diplomacy rather than empirical board-Diplomacy is a risky endeavor, as, like in any case which does not involve mathematical certainty, severe theoretical mistakes could be made accidentally. It would be wise to wait until a large number of WTA games are played (and see if they contain an unacceptable number of draws) before changing the scoring rules. Likewise, it is probably a good idea to see exactly what percentage of the userbase here finds an unacceptable rate of draws - if 70% of games end in draws, but 70% of users have no problem with that, then a change is silly.
IV. If, at long last, one wants to change the scoring rules in order to encourage victory over draws, the most straightforward way of doing so is simply to institute a "draw tax," in which less of the pot is paid out in game endings with higher numbers of players, and more of the pot is paid out in game endings with lower numbers of players. The exact percentages could be determined after more empirical data is in (and the exact problems with player behavior are determined). On the other hand, if even a significant minority prefers the current setup, it would be wiser to separate WTA and taxed-WTA. This, of course, increases the complexity of the rating scheme, but I think that's an acceptable cost of maintaining a style that accurately reflects the intentions of the game itself.
V. PPSC sucks :P