Definitely an interesting question. Some things that may explain why --
Mongo was always AGPL and relicensed to SSPL. This had the following consequences:
* Very few companies and zero large cloud companies ever attempted to run the MongoDB codebase in production as a managed service, other than MongoDB the company.
* Mostly because of the above, MongoDB did not receive many code contributions that did not originate from within the company. There were some, but not nearly to the extent of the others you listed
* The difference between AGPL and SSPL is not nearly as large as the difference between BSD and SSPL or Apache and SSPL.