I will not put such pretty picture about US airlines. It is true that when weather condition is developing, such as hurricanes and storms, airlines in the U.S. will issue weather advisory and regardless of a flight is cancelled or not if your flight is on a date mentioned on an advisory and travel through an airport which is mentioned on an advisory then airline will allow you to change your flights without penalty. However, those cases airlines will rebook you on their own flights only, airlines will not rebook you on another airlines with different routing.

I live at Boston and winter snow disruption is annual event and every time local news will have passengers stuck not able to leave Boston because all the flights for next few days are totally booked solid because of mass cancellation by a storm. When hurricane hit it is usual occurrence that tourists on Caribbean islands are stuck for few days not able to get back home because there simply no flight available with open seats.

If you read FlyerTalk post then you will see that today it is common practice by US airlines that airlines will not waive non-refundable or non-changeable restriction if a medical condition prevented from taking flights (even with a doctor's note) or there was a death of immediate family (even with a death certificate). When you bought a ticket, condition is there and there is a travel insurance to provide monetary compensation in case of irregular events.

I do understand situation is frustrating, I have been flying internationally for more than few decades (show my age ), and especially with internet today we will hear other people's story which sounds like they were treated better. But often the reality is other side always look greener, but...