No Married Persons

[Inziladun]

Originally Posted by Alcidas

Legolas, Gimli and Boromir have been selected precisely because they have no marital ties. It is possible that they may have been selected to attend the Council by their respective leaders because they are free of these ties. With the hobbits it is a little more complex, but the process is akin to that of natural selection.

I agree that the Council's members were "chosen", but it seems that the choice was the work of other powers ultimately than any leaders.
Granted, Legolas was sent by Thranduil to Rivendell to explain Gollum's fate, and Boromir's purpose from Denethor was to get the meaning of a dream, but there was no expectation on their part that they would be going off on any sort of quest afterward. Elrond stated that the Council was "called", but not by him, so I think it's clear that the Fellowship was also assembled under the direction of some other mind.
That said, I would agree that an unmarried status might have been a qualifier.