I deliberately didn't say that the majority of LessWrongers would give that answer. Partly because Lesswrong is only about 1/3 computer scientists/programmers.

Fortunately we have the census and the census does ask for the profession. Among those with the profession Computers (AI), Computers (practical: IT, programming, etc.) and Computers (other academic, computer science) 14.4% think that unfriendly AI is the biggest threat.

Lesswrong isn't a community that focuses much on bioengineered pandemics. Yet among those computer programmers 23.7% still think it's the greatest threat.

We are a community that actually cares about data.