Whether or not the survey was representative is a matter of opinion. While Moot is the head of the 4chan community he's not really placed to know what the 'real' data is more than the next person.
The bigger story here is that by encouraging TechCrunch readers to take the survey from a link on TechCrunch.com, Alexia Tsotsis has ensured that the results can definitely not be considered representative going forward.
I'm left wondering whether that was an act of intentional maliciousness or just plain stupidity.