Yeah, but if you fly UA all the time, it's often real PITA to get to the CO club in another terminal. I'd rather pay for drinks than walk a few miles or take some shuttle to another part of the airport.

As for the OP's question ... there's no way to justify it. She stays home most of the time while you travel in comfort. That's why I'm forced to join with miles (something my wife has no idea about). As long as I'm not spending $$, she couldn't care less.