First, I would like to say the "murder" dilemma has been around a long time in D&D. Many early adventures had non-combatant monsters present in various lairs (usually females and whelps), and players were often put into the situation of deciding whether to cut them down or let them survive (potentially to have the next generation cause the same problems later). There were never any good solutions for this, nor were there ever intended to be. Alignment shifts were a serious thing (loss of level in AD&D IIRC), so people had to consider the consequences of their actions carefully.
Second, you shouldn't necessarily impose modern morality in your fantasy. There are things are absolutes in a fantasy universe that don't hold true IRL. We don't have evil dragons that can destroy huge swaths of the land with few people capable of challenging that. Most of us don't live a few miles away from bandits and evil humanoids that want to raid and pillage our homes. Hell, it's hard to get some people today to agree on whether killing is moral or not (the pacifist vs. soldier argument, or the death penalty argument for example).
Finally, I think it's a matter for each group to decide what they want out of the game. For me, it's immersion. I get into the role of my character, whatever that might be, and while I generally try not to make disruptive characters, I play the character to the fullest. If he has few or no qualms about killing, then I'll wade through the blood of my enemies with a grin on my face. If he's a tactician, he'll probably try to take the leader alive for questioning. If he's more squeamish, then I'll probably try to avoid causing loss of life, but I probably won't object to someone else "cleaning up" after me (to avoid party conflict).
Second, you shouldn't necessarily impose modern morality in your fantasy. There are things are absolutes in a fantasy universe that don't hold true IRL. We don't have evil dragons that can destroy huge swaths of the land with few people capable of challenging that. Most of us don't live a few miles away from bandits and evil humanoids that want to raid and pillage our homes. Hell, it's hard to get some people today to agree on whether killing is moral or not (the pacifist vs. soldier argument, or the death penalty argument for example).
Finally, I think it's a matter for each group to decide what they want out of the game. For me, it's immersion. I get into the role of my character, whatever that might be, and while I generally try not to make disruptive characters, I play the character to the fullest. If he has few or no qualms about killing, then I'll wade through the blood of my enemies with a grin on my face. If he's a tactician, he'll probably try to take the leader alive for questioning. If he's more squeamish, then I'll probably try to avoid causing loss of life, but I probably won't object to someone else "cleaning up" after me (to avoid party conflict).