MySQL is easier to install, much simpler to use, easier to manage and most importantly every little issue has been solved online many, many times over. It's a known quantity.
Fact is that simplicity is more important than features for most people.
Fact is that simplicity is more important than features for most people.
Configuration is a different story. When you are done with a Postgres config you have a more secure setup. They don't allow you to shoot yourself in the foot by default.
Honestly, installation as a differentiator between databases is a seriously weak argument. If you're going to troll pick something a little more technical like acid compliance or something else that nobody seems to care about.
And you ignored Windows, Mac as well as the huge number of LAMP based installers. Being able to quickly get the entire stack up and running very much helped the popularity of MySQL.
Meant no offense. Seemed trollish but when you factor in development setup then yes MySQL is slightly easier. I think heroku is doing a good job making Postgres a snap.