Cuba is a geographicly strategic location. It sits right in the middle of the Caribbean and makes up one side of each of the three choke points which allow shipping to/from the Gulf of Mexico US ports.

A hostile regime left on its own could become a major threat to the US economy by making traversal of those straits hazardous to US shipments. This is major commodities. Petrochemicals, agriculture, raw ore, fertilizer, etc.

There is always some political angle, but the adults in the room are generally aligned that Cuba needs to either be friendly or at least be impotent.