[gen220]

My impression, as somebody who's had to choose this layer of infrastructure a few times.

Many people who "start" with those database choices either (1) "end up" elsewhere or (2) are perfectly content with treating their database as a SaaS business expense.

Their communities have self-selected into a [profitable] niche that excludes the kinds of people (like the author of this blog post) who are both capable and motivated to maintain a fork.

The author of TFA would probably categorize MongoDB as "software I hate" (a category he touches on in the article), to put it in perspective.