I actually did explain this, probably more than once, and now lati0s has even explained it too, but I'll do it again anyway. this will be my last explanation, though.
"A good move brings a player closer to winning
Players who make winning moves should be rewarded
A loss for making good moves is not a proper reward"
The second and third statements are both made redundant by the first. You define a "good move" as one that brings a player closer to winning (that's fine). Then you add that players who make winning moves should be rewarded-- but you already dictated that they are inherently rewarded (they are, by definition, moves that bring a player closer to winning, which is a reward). You then suggest that it is wrong to reward good moves with losses-- well, yes, but that is already evident in your initial definition of "good moves" as "moves that bring the player closer to winning."
You're left with "a good move brings a player closer to winning," "players who make winning moves should be rewarded," or "a loss for making good moves is not a proper reward." You can choose whichever one happens to look nicest to you personally, because they're ultimately more or less the exact same statement. None of them have anything to do with the Self-KO Clause, because under the Self-KO Clause, moves that force a "tie" are not good moves, nor do they bring players closer to winning. They are just moves that force a an unrecognized "tie" situation that actually results in a loss. You can see that your statement("s") really don't say much about the Self-KO Clause at all, let alone that it is somehow "uncompetitive."
Now, if you were to replace "winning" with "the ultimate and supreme goal of Pokemon that can never be questioned," your first statement (again, all three statements are identical; I chose the first one because it most easily lends itself to this demonstration) would cease being completely irrelevant and would become circular instead. It would be circular because the "ultimate and supreme goal of Pokemon that can never be questioned" is something that you made up, and have justified only with the assertion that "in Self KO Clause-less rulesets, a player wins when he KOs all enemy Pokemon. This win condition, and none other, is the great and powerful Ultimate Goal of Pokemon," and then you trail off about how win conditions are somehow synonymous with game mechanics and I lose interest. Sans the crazy "win conditions are game mechanics" thing, the argument is circular, though if I do happen to count that as part of your argument, it would indeed stop being circular. Unfortunately, doing so would not be generous of me because it would imply that your entire argument is based on one of the craziest, wrongest things I have ever read on Smogon. So I won't do that, and instead I'll just say that your argument is circular.