now I need to form a hypothesis how "normal" people, who like them, think.
Easy.
Forming judgements is hard. Evaluating facts and converting them to your preferences takes time, energy, and some qualifications. Taking the ready-made value judgment someone is offering you with a ribbon on top is a low-effort path.
No, this is too self-serving. The most realistic interpretation is usually the one that does not make you feel better than others. I would propose this: http://lesswrong.com/lw/m7l/we_should_introduce_ourselves_differently/ce51
I told an intelligent, well-educated friend about Less Wrong, so she googled, and got "Less Wrong is an online community for people who want to apply the discovery of biases like the conjunction fallacy, the affect heuristic, and scope insensitivity in order to fix their own thinking." and gave up immediately because she'd never heard of the biases.
While hers might not be the best possible attitude, I can't see that we win anything by driving people away with obscure language.
Possible improved introduction: "Less Wrong is a community for people who would like to think more clearly in order to improve their own and other people's lives, and to make major disasters less likely."