Why are Deanna Troi's mother and Mr. Barclay not present at her wedding ceremony portrayed in Star Trek: Nemesis? By the end of Voyager, Troi and Barclay seem to get along pretty well, and Lwaxana is... well, her mother. Will's father is not present either.
Is there an in-universe explanation? Is there a real-world explanation? Were the characters even considered for participation?