Bart's abstract came down to "A lot of the problems with writing desktop applications are made much worse by using inappropriate programming languages (such as C/C++). I will review some of these problems, discuss alternative languages, and make suggestions about what to do about it all."
Bart brought up open questions concerning why desktop applications are harder to develop than for mobile/web and whether the choice of programming languages is to blame. Bart continued to share his views on different programming languages, shortcomings in his view, and then some feedback from XDC2012 attendees.
Overall it wasn't really X11-specific at all, but just Massey sharing his general programming thoughts. If you're curious about his opinions from academia, the video is embedded below in two parts (there was a power outage to the building part-way through the presentation).