This is a fascinating train of thought. I get the logic, but where does it stop?
If the idea is that any situation where people are influencing the government/making decisions without absolutely everyone in the electorate being involved, is anti-democratic, at what point are people in the government allowed to make decisions without consulting everyone?
We have representatives for a reason, and part of that reason involves making decisions without having a vote (even when that decision is made by someone several rungs down the chain from the person actually elected).
I'm highly sympathetic to the idea that the actual effect of these types of "public comment" situations and hopefully anyone involved in one keeps in mind the inherent biases of who shows up, but I don't see how you can flat out deny the idea of asking people, you know, the voters, to come give opinions on decisions being made that are inbetween the actual elections.