Keith A....

A dictionary editor can print anything he chooses... that doesn't mean he is speaking for the rest of the world.
What are you missing? Go ask partners who are limited to "civil partnership". Then ask people who are legally married why THEY didn't just limit themselves to civil partnership. I'm sure they feel that full marriage rights are preferable. In many places civil partnership does NOT allow full legal rights on inheritance and various other rights.

The ONLY reason to restrict legal marriage to those YOU approve of is to make your own situation seem superior... and to hang on to religious beliefs that are relics of a different age.