the promise of the bank was a bit of a failure since by the time you've gotten so very old that a Nobel could've been awarded you are also so old your sperm is lower quality; etc.

This suggests a better way of establishing a eugenic sperm bank: approach the recipients of early-achiever awards such as Peter Thiel's 20 under 20. And perhaps also encourage these people to mate with each other (if they aren't doing so already).