Comment by danudey

MySQL installed with skip-networking was very common, but as soon as you need to access it over the network (e.g. when you move from one box with MySQL and PHP to one for each) then you have to enable networking and everything falls apart.

Also, the number of times in my career that I've googled a problem and seen some forum post saying "Oh, just run chmod -R 777 /var/www/wordpress/uploads/ and it'll fix that" "Great it worked thanks!" tells me that it's the blind leading the blind out there and I'm sure there's tons of forum posts telling people how to disable authentication on their MySQL and disable iptables on their server so that their PHP app can connect to the DB without a password.