Whoa whoa, MisterV, let's keep the language mild.
First, what crazy system of ethics are you using? IF SC let people gain direct advantage in battle using money (which they don't) it wouldn't be unethical at all, unless you were maybe forced to play the game and you lost money for losing or something.
Second, nobody who enjoys the game without spending money ends up spending money on the game- they just stop playing. If they do like it, they can pay money to reduce the amount of time it takes to progress. That's the only thing you can buy in this game, time. SC does this because they're intelligent and the game is much more successful than it would be if the game was pay-to-win.
In terms of global rankings, yes, you have to spend money to stay at the top, but that's a side effect of the game's bias toward attacking (by which I mean the fact that a skilled player will usually win against a base designed by an equally player at the same level of progress in the game) which, given the asynchronous combat style, makes the game for fun for everyone over all. I'd go so far as to say that SC has sacrificed metagame balance in high level play in order to balance the metagame for the mid-game (
800-2400 trophies) which is exactly the opposite of catering to gemmers. Do you think that the game Jorge Yao plays is more fun than the game you play? I don't.