If it was in the past, as long as the government and the military gave him a good incentive and treatment, Bai Zemin might have been willing to work together with them. After all, the human race was in danger of being completely annihilated and if he received the support of the military and the government it might be much easier for him to reach Changping District where his family was located.
The problem was that Bai Zemin alone simply did not have the ability to reach his family on his own. Yanqing District had approximately five million people before the apocalypse and because it was an ecological area the forests were numerous.
How was he alone to face millions of zombies and countless mutated and evolved beasts? Even if he was strong, it was clear to Bai Zemin that overconfidence would only kill him sooner rather than later.