Denethor's treatment of Faramir tells us much about Denethor, but only because we already know much about Faramir (and come to learn more). Without this knowledge, we would have no way of knowing whether Denethor's treatment was just or unjust.
With Orcs, it is much the same way. You've claimed before that Legolas and Gimli's game tells us more about them than it tells us about the Orcs, but this is not so. If Orcs are completely evil, then the game tells us simply that Legolas and Gimli don't fear them and are gung-ho about ridding the world of them (and this is perfectly fine and acceptable since the Orcs are completely evil). If Orcs are not completely evil, however, then the game tells us that Legolas and Gimli are monsters for whom terms like "hero" or even "good guy" are thoroughly inappropriate, and their boat sinking in a massive storm halfway to Valinor would be an end too good for them, curse their memory.
Now, it is true that this alone would not tell us which possibility is the true one. However, since the rest of the text shows us that Legolas and Gimli are, in fact, heroes--and since the game is presented in keeping with their heroic nature rather than a deviation from it--I prefer the former reading to the latter.