If it had read more like "I left because I was frustrated with code quality", and actually took ownership of the feeling, that'd have made a big difference. It reads more like "i left because the code sucks, everyone around me is dumb, and our users are sheep"
I don't think anyone's going to suddenly switch to postgres as a result of this blog post...so really, what's the point?
Maybe it'll get more attention on the systems he called out? Probably not. The post just reads as bitter, mostly about the mindset of other contributors, but doesn't outline what they tried to do to change the hearts and mind of those contributors. Or put another way: what did this person do to lift up all of these people? Deriding doesn't actually help anything.
If the goal is just to vent that's fine, but there's really not much else to see here.