Consider these real-life scenarios:
It's the week of your trip and the news shows that the storm of the century is causing evacuations at your destination. What happens if you can't use the travel arrangements you've already paid for?
You're walking up a flight of stairs at your rental and lose your footing, breaking your leg. Where is the nearest hospital? How will you pay for the medical care you need or emergency medical transportation?
Your luggage with your sports equipment never showed up at baggage claim and you may not get it for another 24-48 hours. Now you must buy necessary personal items and clothing, as well as rental equipment for your sports-related activities. Can you get reimbursed for this?
Your child or another covered family member has a medical emergency that prevents you from going on your planned trip. What will you do with your non-refundable travel arrangements?