Are you entirely certain there is not another genealogist hiding in the list of your relative’s descendants?
My tree is online at Ancestry.com. I blog about my ancestors on a regular basis. I have tested my DNA. My ancestor table is on my website. And yet today at a family reunion, I discovered another descendant of my 2nd great-grandparents who is interested in our mutual family history.
If it’s been a while since you looked for interested kinfolk, is it possible that someone has recently developed an interest?