An air ticket is a contract between the airline and the passenger. That's why there is a contract of carriage. Unfortunately, the norm in the US is not to not allow name changes at all. In Asia, you actually can, at least on some tickets (I think my last ticket on Thai actually allowed it to be done for ~$50).

Unfortunately, that's not going to help you. Even canceling the ticket won't help, as the credit generated will only be useable by the original passenger (at least, initially).

In the end, why they don't allow it doesn't really matter, unless you plan on legally challenging it.

My sister is actually going through something with Aeroplan - she recently changed her last name (including on documents, etc.), but booked the ticket using both of them. They are actually willing to let her pay the re-issue fee to have it changed - but she doesn't want to. We'll see where that ends up.