What you just stated sounds all well and good...but its not very informed. Or maybe just informed from 10 years ago.
In general a database is pretty much as good as its DBA. That said, your statement about Postgre being vastly superior is strictly a contextual one, and even then would be a trade-off at best case.
For the DBMS corner cases that MySQL doesn't do, there are some incredibly important things that Postgre doesn't do.
I see in the updates that Postgre is finally doing Streaming Replication? Just now? Before this, you had to rely on 3rd party "hacks".
Meanwhile, MySQL has done instant replication and failover for quite some time.
More importantly, MySQL has done Master/Master replication for years now, natively, with relative ease. I have been doing Live Hitless upgrades to sites for years now, to infrastructures built on MySQL. Sites doing 5-10k questions per/sec. on minimal hardware(relatively). No Down Time. That is huge when it comes to "stability" of a website or web application when everything is DB dependent.
Don't get me wrong, I like Postgre. I have for years. But don't go around talking the old line that MySQL is an severely incomplete DB for the ignorant. It has matured over the years into one of the most capable, feature complete, stable, and useful databases available.