I think artillerymen are most exposed to the threat of shrapnel, wherever it's coming from, and that's what most common body armor protect best against now days.
Also, I don't see how the cost-saving method of limiting body armor usage is an "excuse" or baloney. Just because China doesn't want to lavishly spend its GDP on expensive body armor on troops that are serving as border garrisons against countries whose military capabilities are a fraction of theirs, or reserve troops who would most likely never seen action on short notice given the size of the active forces, doesn't make the procedure an "excuse".
If the PLA is willing to spend the bookkeeping costs to save money so the country can spend that money elsewhere in civilian investments, I don't see why anyone would blame them for doing that. It's not that they "lack" the money; they are just using it more efficiently with simple accounting practice.
The analogy to "why does China need rifles or tanks in peace" does not make any sense. Those equipment require much training to be effective and constant practice to master. Wearing body armor doesn't take training, except for getting used to the weight, which is easy to find a cheap alternative for. You can't make a cheap alternative for a rifle that you can train with the same effect on.
The same goes for tank armor. ERA is expensive to maintain, so in place of ERA they use modular armor during peacetime. There's no point to putting ERA on every tank or body armor on every soldier during peace time. It's a waste of money.