It sounds like you're no better than your hunting group in regards to your ethical standpoint on hunting and making a clean quick 100% shot. If you're fairly new to deer hunting, just remember that even though the old guys in camp are shooting running deer and
sometimes hitting them, it doesn't mean you have to start trying it for yourself if you're unsure of your shooting abilities. When you said they
miss more deer than they hit because they don’t know how much to lead them
it only tells me that they're fools, plain and simple. They aren't hunting deer at all, so don't even call it that, they're shooting
at deer.
If you're tossing out a few shots all your doing is guessing that you hit it. See blood? Great you hit it... where did you hit it? The vitals? The guts? Blow its udder off? Who knows where you hit it. What happens if you don't see blood after the first few yards? Toss it up as a loss? What if you had actually nicked the deer or shot it in the guts and it runs a few clicks away and dies? What a waste that would have been.
How embarrassed would you feel having 20 people look for a deer that you think you shot? What an absolute waste of their time and yours. If everyone helps look for that deer, that could be 20 hours or more combined hunting time thrown away. How do you feel taking an hour out of your prime hunting time to look for someones deer that they gut shot because they didn't know their limits. I personally wouldn't be too impressed, especially since they can just wait till a better opportunity comes up later in the week.
Get pissed off, I don't care. I'm not the only one here with this view.
If you or your friends haven't finally got the nack of it yet, don't keep trying it every year with poor results.