Who knows why some family members want copies of speeches - and pictures, newspaper articles and obituaries - and others don't.
It could be that they feel they can get a copy from someone else if/when they need it. Or maybe they just didn't think about asking for a copy. Or maybe these kinds of things - copies of speeches - just isn't their cup of tea.
It's hard to believe, but not even all family members enjoy or appreciate a family reunion, let alone a speech given at the reunion.
Regardless of the reasons for not wanting a copy of your speech, don't be offended. Just chalk it up to their loss and appreciate the fact that you were honored with the chance to part with some of your thoughts and wisdom.