ACTUAL good? I don’t know. For me it is a hobby. Some people collect stuff like lunch boxes or beer cans. Some people drink, some people paint. I love history and geography. Collecting names and dates is interesting, but understanding the historical events and circumstances that have occurred in my family is terribly interesting. From the Bataan Death March to the Protestant-Catholic conflict in Ireland to the Prussian rebellion of 1848-49, family links make these otherwise foreign events more personal for me.
That's nice. However, the tendency of the LDS church to tout the genealogy files as a "great service to mankind" when they are, in fact, a tool for collecting names for the baptism for the dead ritual, is quite mendacious and misleading.