Pogue Mahone:

Most people don't have proper sit-down dinners, then. Even the strictly formal dinners I've been to always had couples sitting next to each other.

Yeah, I've seen it way too often, too. The point of breaking up the couple is to prevent them from subverting the party by talking about the second-grader's homework, the new drapes, and did you get the dog to the vet, until some brave soul stabs them in the eyes with a butter knife.

Couples need to mingle at parties. They see enough of each other at home.

Of course, that just supports the OP's point that each person should be treated as an individual, not half of a couple.