There were survivors of Hiroshima and Nagasaki. And there are ways to soak/disperse radiation.
I'm referring to the situation of Mutually-Assured Destruction. Hiroshima and Nagasaki were different because no other nation had employed nuclear weaponry (it is believed that the Nazi's experiment team had decided against experimenting with atom-splitting, but that they had the potential to develop a nuclear device, and it is known that Canada and the UK had nuclear programs and in 1943 the USSR began their own in response to discovering ours, the UK's, and Canada's). Since so many people are ignorant about nuclear warfare, let me explain:
Following the testing of nuclear devices by the Union of Soviet Socialist Republics in Semipalatinsk, Kazahk SSR, the fear of a NATO-USSR nuclear confrontation began to rise. During the 1950s, many people started trying to come up with ways to "survive" a nuclear war. However, modern research has shown that even with the low-power bombs used in the bombings in 1945, a large-scale war would
field no survivors of any kind. No humans would survive, no animals or plants would survive. The Fallout series plays off of the ignorance in the 1950s that we could have survived by living in bunkers. Here's the issue:
radiation is powerful and pervasive.
So, your statement actually follows 50's logic rather than actual science. I'd rather we go with this - a server where everyone is constantly dead won't work well.
Exhibit one:
Radiation disperses over time. There will be survivors of an atomic attack, as witnessed by the previously mentioned incidents. Fun fact: you can visit and tour certain parts of Chernobyl. The radiation measures very low in areas covered by snow, but spikes incredibly when you remove the snow from that same spot.
You're assuming that:
1) Some majority of major nuclear powers, similar to the situation in our world, would detonate some large number of their weapons. In this case, yes the world would suffer, and the majority of species would die. Over time. Not all of it would be immediate, and not all of it would necessarily die until the atmosphere was reasonably destroyed, which would still take some time. (We could be playing in that time, especially since it may all come to an end depending on how the server goes.)
2) The world we get to play in involves anything more than 1 target suffering 1 attack. Given the area we get to play with (5.2km, btw) to make a realistic comparison, we are all squashed into an area less than the size of the average farm size in Saskatchewan. If a nuclear weapon was dropped on the actual map, most of it would be completely incinerated. Given we have ruins and debris, our map is at least a few km away from ground zero. Radiation and inhumanity would be the major concerns, as they are. And as stated above, radiation decays over time, at an exponential rate. We have no way of knowing, and will never know, what the entire rest of this solitude world looks like.
3) That logic and science since the 1950's have both been completely thrown out the window rather than adjusted and built upon. I'm sure the defenses they were trying to design in the 1950's were based on no more than a few such weapons being used, likely with the intent of surviving an attack similar to what happened in Japan,
which had survivors without any such defenses. Modern research showing that a "large scale" attack can't be defended against is almost meaningless. That's like saying your roof just won't work against rain because an ocean might drop on it all at once. By the 1970's, when multiple nations had pumped out a lot of nuclear weapons, the idea of defending against all of it becomes meaningless. This doesn't mean that what was done in the 1950's is wrong, it means that it has no application anymore.
Since "so many people are ignorant about nuclear warfare", I think you should do some research. Obviously, nuclear war at this time could be devastating to our entire world, and must be avoided. The expectation that everything will die as soon as any amount of weapons are detonated is completely wrong. It will depend entirely on the scale of the attack, the power of the weapons used and the targets chosen. Weapons have been tested and used. We aren't entirely dead yet.