He's probably referring to the idea that much of the complexity around today is not particularly useful - in particular, that programming with values rather than variables makes understanding a program substantially easier.

Simple Made Easy is a talk by Rich Hickey, the author of the Clojure programming language which encodes a lot of these ideas into the language.

http://www.infoq.com/presentations/Simple-Made-Easy

[EDIT: ambiguous comma :)]