Why? Because my intent can change. I intend to buy the Empire state building, but who cares what my Intent is? Many traders and Brokers treat a Letter of Intent as if it were holy writ. This is a critical beginner's mistake. As its name indicates _ this document expresses an intent.
The Letter of Intent is not binding, and rather silly at the worst of times. An LOI by definition only registers intent to purchase, and it specifies this intent weakly, and due to its ambiguity should be avoided.