What is this?
One of the fundamental purposes of language is to allow us to agree on the meaning of words without negotiating them each time we use them.
Why is this important?
When negotiating things we often assume we are in agreement with the other party regarding the words being used but often the meanings differ significantly. Fuzzy language is particularly susceptible to large gaps in meaning between the two parties involved. For example: ASAP may mean immediately, this afternoon, tomorrow, next week or any number of things to two different people in a negotiation. Discrete values do not lend themselves to this incongruency in understanding - one means only one, tomorrow at 10:00am does not give much wiggle room unless one disputes time-zones and so on.
Using specific values and objectivity in our speech will significantly improve problems with ambiguity and mutual misunderstanding. Additionally, we can verify our meanings with one another to make sure we are talking about the same thing when negotiating to reduce misunderstanding. This is often seen as slowing down communication and therefore to be avoided - but the cost of do-overs, renegotiating, or in severe cases court settlements often far outweigh the costs incurred in slowing down and getting clear understanding devoid of faulty assumptions.
People who seek to defraud others will often balk at efforts to slow down communication and clarify words, times, amounts etc. because the "gray areas" are where they work to create confusion, misunderstanding and faulty assumptions for their victim.