Hello Amanda et al,
At Caltech our decision to drop the ProQuest mandate met with no opposition or questions -- the policy was well received because it aligns with our other institutional OA policies to make Caltech research openly and freely available. Mandating paywall access for graduate works is anathema to our vision and values; our community fully understands the reasons for not contributing our dissertations to a commercial database maintained by a for-profit company.
American dissertations were never intended to be monetized and OA repositories, both institutional as well as community ones such as Zenodo, are perfectly well suited to disseminating and archiving them. Moreoever, with our own dissertation platforms we can more effectively handle the rich array of data, visualizations, code, and other components of responsible, reproducible, reuseable research that Caltech strives to produce.
There is a well-established and heavily cited literature documenting reasons for OA ETDs; for supporting student choice in disseminating their scholarship; and for avoiding commercialization of these works. References have been posted to this group on numerous occasions. Please feel free to reply or get in touch directly for pointers to this evidence supporting student preferences to set their works free (albeit, with limited embargoes in some cases to enable formal publication in journals or books).