Honestly, I can see both sides to the argument.
For one, if we do offer a zombie medal it would be logical to offer a medal for all of the spoils options. I agree that it could seem a bit much to some people, but what harm does it do?
The medals are already a bit extreme if you ask me. But there is nothing wrong with that. Find me one person who doesn't enjoy obtaining a new medal. It's the reason we (some of us) play. It's fun to have acknowledgement of your achievements, so why not give people more medals to strive for. I think it would encourage people to play new settings and hopefully boost the number of new games created.
Realistically no one is ever going to catch Josko and the others at the top of the medal scoreboard, so we might as well add more medals to the list.