There is the risk that you are the lemon, and selling warranties can also turn into its own lemon market (Analogizing this to insurance markets with high levels of fraud).

Some thoughts. Apologies if any of this is overconfident, trivial or otherwise unhelpful.

• You did not go to the common man. You went to the confused philosophy enjoyer. By default this is what a philosophy meetup is since most of philosophy is confused. 
• It seems like you spent your time there caricaturing them instead of gathering information.
• Perhaps this metaphor is flawed or irrelevant somehow, but you don’t get better at chess by discussing chess moves in a group (citation needed). I suspect that you have some expectations about group reasoning that are unrealistic.
• Something you can do: Help others debug. You have the tools, maybe you can share them. Perhaps poll for a belief in belief?
• It takes time to warm up to a group. This post is not unlike what I read from people describing first dates or going out to make friends (The disappointment part of it anyway). Object-level your first impressions are probably correct, but maybe you’d feel differently about your misanthropy later.
• This is how I feel at rationalist meetups sometimes. I don’t hold as much contempt as you do though. If it was intellectual rigour, and seriousness for truth that really decided how I feel about people, I’d dislike much of my family, friends, coworkers, and myself. But my VP wrote me the sweetest letter after christmas break, and my brother makes excellent yerba matte tea that I still can’t replicate. Perhaps you are different though.

"I didn't hear that" when people's low level processing fails to parse words someone said despite being perfectly able to receive the audio. not usually playing fool, in my experience

That’s why I appreciate a “hey” or some other initial phrase before someone starts speaking to me. It gets me ready to parse words. For some people I talk to if I start speaking without that, I’ll mostly get a “what did you say?”.