Incredibly risk averse.
It's risk vs reward. A new resort is incredibly expensive in this day and age. I don't think we even have close to what the final cost is for Epic Universe, but it's a lot. They have a resorts all over the world already. If they opened another European resort for example, you're risking cannibalizing Paris. Universal can do things like open a park in the UK because they don't have a European footprint, so there's no cannibalization there.
Almost every place that has the capital, population and willingness to work with Disney has had a park built. Also it's a risky investment with the how the world economy is today.
Cruises are a cheaper way to make the brand more global with less risk.
Yep this right here. More ports and more ships means more guests to service. Cruises are a money faucet and until it shows signs of slowing down, that's what they'll keep doing.