There are reasons to choose PostgreSQL over MySQL (and vice versa), but the article is certainly an example of unfair evangelism.
A lot of the evangelism against MySQL is rooted in a deep skepticism against letting a DB that would even have such a feature, much less leave it on by default for years after sort-of admitting that it's probably a bad idea, anywhere near your data. I loved MySQL back in the day when it would work straight out of the box on both Windows and Linux (and god knows not a lot of web software did back then), and Postgres was always, frankly is still, a bit opaque to actually get from zero to one. But I also remember discovering the varchar overflow and the users being pissed at me for losing their data. Luckily it wasn't a really important field and we discovered it reasonably fast, so fallout was contained. But the same app actually dealt with payments, it could have been much worse.
It's basically a country song: MySQL is the kind of guy that's tons of fun, always the centre of the party, but used to disappear for multi-day benders without a word, but have now cleaned up and is disappointed that his high school sweetheart prefers the boring guy who went to college, got a job and was never late for a date.