I can see letting someone go home after a good fight. On the other hand, when I'm in a good fight, going home is not really on my mind. I just slug it out until I can't fly my plane anymore, and in a good fight, the other guy is usually doing the same. I'm not gonna stop just because my oil is it, leaking fuel, flap gone, aileron gone, etc. It's only because I place less emphasis on returning home.
It comes down to how you want to play the game. Feel free to pretend your in a real war with real lives and mix in honor if that is your cup of tea. Lots of people define in game honor as different things. Your just not going to get everyone to fly to the exact same "code," as that code varies largely on previous game experience and how you go about playing the game. For example, a guy only interested in pvp combat might view things such as vulching, spawn camping, HOing as dishonorable forms of gameplay. On the flip side, playing from a stategy end of things vulching and spawn camping are a form of denying the enemy an area. Not even going to get into age groups.
As for shooting chutes....ya, I do it. I don't really see any issue with it as I don't see the pixel as a real person. If you land in your chute....do you then walk back to an airbase? If you see a plane coming towards you, you can .ef in chute. This will deny the chute killer and saves you from having to walk back to your base. Besides, the chute guy is an armed combatant

Also of note, chutes can also be factors in a fight, communicating with their team....something that WW2 pilots couldn't do.
Now, if I was a real WWII fighter pilot I can say that I wouldn't do such a thing. Then again, many terrible things happen in real war, even comitted by otherwise good people.
Fortunately this is a video game. Everyone can just relax and have fun.