Outside of Rob's points which I found valid (you can see it in the video) the one thing that bugged me is the aggressiveness of Facebook. It appeared they felt we should be impressed that Facebook runs on MySQL not PostgreSQL. That somehow Facebook validates (or Google) the argument for MySQL.
The problem I have, is that Facebook data is worthless. It isn't worthless to them obviously. They make money selling your data (same as Google in a horizontal way). If Facebook loses your data. It is not a big deal. If your bank loses your data, that is a big deal. Financial institutions don't run on MySQL and for good reason. They do however, run on PostgreSQL.
To be fair, MySQL has its place and as you will see in my rebuttal, I don't hate MySQL. There is a lot of people that make this mistake. Never mistake apathy for disdain.