Personally, I think that if you desert, whether in the first 30 seconds or the last 30 seconds, you should not get any rewards, PERIOD! If I desert, I really don’t care if I get any rewards, I am quitting either because I refuse to play against opposition with two level weapons advantages over me, or I am just so totally frustrated that if I stay, my computer is at risk of destruction. 
An example of a game I desert? I’ve played two minutes, lost six squads and only have three kills. You know, one of those games where you can’t take ten steps without your entire squad being vaporized. 
So, why don’t people want to take the loss? Is it because they don’t want it to effect their w/l%, or their game rank? I’d say both. I would shit can the ranking system. At least for me, I just want to play and could give a s**t about my rank. Yes, I always obtain Marshall, just because I am retired and can play a lot, but I would play the same amount if there were no ranking system. And the w/l%? Personally, I always just assumed that everyone that claims to have an overall w/l % over 75% was either always playing in a stacked group, or deserts a lot. 
My TOTAL win/loss percentage is just under 61%, and I don’t desert a ton, and over half of my over 4,500 games were with the Allies.
Off subject a little, but in my three years of playing Enlisted, my first year and a half were done TOTALLY FREE…I only played Allies, and never spent one cent on this game. I NEVER deserted, in fact the thought never entered my mind because I was playing for fun. Playing solely with the Allies I was damn near always in the lower 30% w/l, but didn’t care. Not until I started buying BP weapons and premium squads did I start to get frustrated with the game. So now with having spent well north of $1,500 dollars in the past year and a half, I get pissed, frustrated and angry far more then I did when it was just a game. Well, now I am going back to my roots. I am going to play less and unless DF offers something that really gets me hard, they’ve seen my last penny. I think I and many players have forgot that this is supposed to be played for fun.