Travel insurance encompasses so much more than just medical needs.....
Last year my DH was unemployed for several months. Thankfully, the vacation was paid for before he lost his job. Had he been able to start a new job during the penalty period for the cruise (meaning he wouldn't have the time off to go), we would have been able to cancel and be reimbursed under the Cancel for Business Reasons clause in our policy.
Bad weather can sometimes close airports and cruise ports, causing both planes and the ships themselves to be rerouted or delayed. Insurance reimburses meals, hotels, change fees, and costs to join the ship at a different port if needed. This weekend's fog delay for the Magic into and out of Galveston is a perfect example. Those who did not book air through
DCL were on there own to deal with yesterday's missed flights. One poster in another thread reported that Air Tran wanted to charge their family $2000 in change fees and differences in fare costs due to their missed flights. They were able to plead their case in the end, but they very well could have been liable for that $2000. Insurance would have covered those costs.
I tend to think of purchasing insurance not just for reimbursement of what I might have already spent. I think of it as a way to avoid the unexpected outlay of (possible large sums of) money I hadn't budgeted for should circumstances not go as planned.