I think his expectation of compassion and sympathy from a large Corporation are misplaced frankly- he can expect that from friends or family, but what he has with Cunard is a business relationship.
I knew before reading very far into this letter that he had not bothered to buy Cruise Insurance and would now demanding reimbursement because of his own neglect. We have all seen this many times on Cruise Enthusiast sites.. Playing the poor health card is tasteless. Lots of cancer survivors out there know better than to travel without comprehensive coverage and don't expect someone else to pay for their mistakes.
For someone who claims to have traveled extensively I am incredulous that he did not purchase Travel Insurance. He has himself to blame.
No doubt some media outlet will take up his cause and they will manage to blackmail the company into providing a replacement cruise.