I'm afraid you're not going to find much sympathy on Flyertalk for your situation. Most FTers believe that is very important that airlines stick exactly to the letter of their terms and conditions, and this is a prime example.
While I agree, where I feel the airlines shoot themselves in the foot is their poor communications skills and their (and their vendors') inability to inform customers about their ticket limitations at the time of sale. I guess they presume it will turn customers off if they clearly present the terms and conditions.
For example, during the ticket sale process there should be a large screen that says something like -
THIS TICKET IS NON-REFUNDABLE AND CANNOT BE EXCHANGED. IF YOU MISS ANY LEG OF THIS ITINERARY FOR ANY REASON, INCLUDING ILLNESS, OR ACCIDENT, ALL SUBSEQUENT LEGS WILL BE CANCELLED AND YOU WILL RECEIVE NO REFUND. THERE WILL BE NO EXCEPTIONS. DO YOU WISH TO CONTINUE?
....followed by a similar large screen that offers you insurance to cover you in this eventuality, and provides a similar message if you decline the insurance.