I think Drop Bear's explanation earlier fits with what you're saying. His point was what I'd term a philosophical one: within whatever limitations you put on yourself, you do your best to win. So, if I decide to defend myself only with my left hand (strong-side injury simulation), then I do everything I can to win within that limitation. The same goes for working within your style, as that's just another limitation you put on yourself...until it's no longer a limitation.The reason why I don't spar to win is because then you'll just stick with the techniques that will allow you to win. If the goal is to win, then why work on a technique that you aren't good at? If the goal is to win, then working on techniques that you aren't good at are just going to make you lose. This is why we often see martial artists revert back to basic kickboxing skills instead of using the other techniques within the system.
If you spar to learn then the focus is to learn how to use the techniques. If you spar to learn how to increase your ability to successfully execute various techniques, then right away you know that you'll fail often at the start, but as you become more familiar with the use of the technique you begin to become more successful with the technique. All of this only happens when you aren't trying to win.
After all why would you use a technique that you aren't good at if you are trying to win?