The letter of intent allows for all facts and figures to be verified so that the buyer understands exactly what he or she is getting in the property. If the buyer finds something that he or she can not accept, or something not originally expected, he or she can back out without any recourse or punishment.
We find exactly the opposite to be true. If you were to go to an unknown area, would you want a map of the area? Well that is exactly what the LOI is: a map of the major deal points. In today's busy world it is important to be sure two parties are going down the same road and in the same direction before spending too much time working out all the details of a transaction.