I'd guess not enough interest. I work for an academic publisher, and I can tell you that that would not be an easy or cheap thing to do, particularly if you wanted to go back to the original manuscripts and do a new transcription. You would need to be sure of a market of a few thousand copies for an expensive edition. The CCP in AZ says they control the rights for the photos, not clear who would have the say for the text (family heirs?).
I worked on an online repository for some 19th century poetry where we have scans of the manuscripts presented with transcripts of the text. It's pretty cool and if someone has a small fortune to donate, that would be a way to go too.
Bookmarks