Many a time, especially in a case involving a supposed seller who is either a fake seller or does not actually have the supposed crude in hand yet, or, an unscrupulous aspiring seller's agent or broker who actually has not acquired a crude supplier (seller) yet, buyers may issue an LOI only to find out that there is no seller on the other end. This happens a lot in situations where you have an hungry agent or facilitator who is still struggling to get a real supplier, and by extracting this LOI from an unsuspecting buyer, this facilitator can commit the buyer only for him then to start hustling to find a seller or supplier.
The Road to Hell is Paved With Hugh Jackman's Letter of Intent. There really is no benefit to seeking letters of intent from actors (or their reps). Producers hate asking for them, reps hate writing them, and financiers ignore them. They're usually out of date. They're not binding, nor are they conditional to anything that's relevant. And yet, they still rampantly persist within indie producing and packaging.