Or are things just different for you, with boards that are in use for many hours in a row with no opportunity to suck the moisture out?
I'll give this a go. regardless of the material,( wood or plastic) bacteria multiply over time, given the right temperature and conditions. In a commercial kitchen, ( or at home) best practice dictates that any food contact surface like a cutting board in "constant" use for 4 hours should be changed out washed, rinsed, sanitized and allowed to air dry. This would also include, knives, gloves if worn, counters, slicers etc.
Basically, one should be breaking their work station down within that time frame. and re-set. Plastic has no special ability that allows it to be in constant use for a longer time frame without intermediate cleaning and sanitizing, nor does wood.
if someone is cutting up chickens for 5 or 6 hours on the same board they're playing with fire. Growth is exponential. Even produce can be problematic. Cross contamination is another topic..