Why is body pH acidic?
It isn't universally so. Bodily fluids come with different pH levels, some acid, some alkaline.
http://bio.groups.et.byu.net/pH_Biological_fluids.phtml gives the following:
The pH of Some Biological Fluids
Pancreatic Juice 7.8-8.0
Blood Plasma 7.4
Intracellular Fluids: Liver 6.9
Intracellular Fluids: Muscle 6.1
Cow's Milk 6.6
Gastric Juice 1.25-3.0