To be fair, this article is about using MySQL as a NoSQL storage and so all of this advice is geared towards that use-case. I'd kill for so much traffic that any of this would be necessary as opposed to any RDBMS best-practices.
I do agree that UUIDs should be stored differently -- the use of varchar rather than a fixed length type for a primary key will hurt performance.
I do agree that UUIDs should be stored differently -- the use of varchar rather than a fixed length type for a primary key will hurt performance.