It is not unheard of for businesses in both the public and private sector to not allow AGPL code or use of applications released under this license.
For example, I worked at a public library for years, and the policy was no AGPL, even if we had no intention of touching the source. Same for a local university.
I agree auth is a huge success, but no alternate DB support is a not starter for most I imagine. Any other non relational DB support would be a huge win, most people that I have talked to are blocked by Mongo's license.