I can understand Rod Roddenberry for wanting to better know who Gene was, because he was around 17 when the man died. I was 19 when my Dad died, I was attending college and living at home, and then suddenly I was legally an orphan (due to the under 21 laws at that time).
Similarly, my biggest regret is I never had a chance to talk to my father while as an adult, and learn from his advice, perhaps avoiding many mistakes I've made in the last 40 years.
There's nothing wrong with Rod trying to earn money from the franchise. I'm in possession of poems my mother wrote before she died in 1965. I keep debating whether to make them publicly available. I really know nothing about her at all except she was a 17 year old from a large family when she married.