Because you can already `shuf -n 1 /usr/share/rig/fnames.idx` (or mnames for male ones) or `vis-menu /usr/share/rig/fnames.idx >> momlikednames.list`, and `cat {mom,dad}likednames.list | sort | uniq -d` to find names both parents like.
`shuf /usr/share/dict/words` was how I picked my HN username.
The list is biased. Not only does it only have U.S. births, but also only those where the individual has a Social Security Number. I wonder how many the latter rules out.
For privacy, it also drops names that are rare, with fewer than 5 births in a given year.