1. Infinite supply of people.
2. 90%+ of times before you get anywhere, you find out the person doesn't have "what it takes".
At minimum you have to filter out 90%+ of people that simply don't have the mental faculties to evaluate what is and isn't a valid argument, before you even get started. All this just takes energy and there's just no benifit.
Its like imagine you're trying to playing chess, but
1. Most of the people don't even know rules.
2. Even if they know (some of the) rules. Some people are fundamentally incapable of recognizing and telling a difference between valid or invalid chess move. Some moves - like castling - are fundamentally too challenging for them to grasp. They simply don't have what it takes to participate.
3. And then you find out whole bunch of people aren't there to play chess to begin with, but rather discuss how the moves they use in their house is all different.
It's just such a waste of energy.