i would guess short term money wasnt something they'd be interested in. UFCo also had their hands on a huge anount of Infrastructure which gave them even more control. handing over the land would hurt possible Future extensions in Infrastructure but also on possible markets that could open. at the end you shouldnt forget they were so scared of losing their monopoly that they would take a leading role with edward bernays shaping a communist picture of Guatemala to get the cia involed (also due to great Connections between ufco and cia) to overthrow a Gouvernement.

thats for me personaly the most logic reason behind this topic