Engineering time is very limited and the support cases are exponentially large. The author wanted MongoDB supported in the hard case. Well, that means you also need to support 4 or 5 other, similar databases the same way.
If you want a bleeding-edge PaaS with corporate support, you should expect to pay corporate prices. If the project / organization doesn't allow for that, then either the requirements or the mindset is off-kilter.
I think the what the author is really mad about is the vendor lock-in. That used to bother me too, until I realized that learning new platforms is done on my employer's dime and not mine.
A few more years, and some other challenge will be on the bleeding edge and this one will be mostly solved, meaning that open-source community solutions will exist that you can build once and forget about it. Knowing most devs, they'll spend all their time complaining about whatever the new edge is instead of marveling at how much easier things are now compared to the 'bad old days' of 2015.