I see KTM as more than a kitchen table; it's a web-based extension of a grocery store or soccer sideline where we can discuss with other parents and teachers without having to rush home to cook dinner. There are always new parents coming into the grocery store. Hopefully they will realize that they aren't "the only one who's complained."
I think parents are very interested in any information they can get. This is the kind of information that many people won't talk about in a letter to the editor. It's also information that schools really don't want to discuss publically either.
For many discussions, there is a niceness factor that gets in the way of critical analysis. If a waiter asks if you liked your meal, most will probably say it was just fine, still tip 15%, but then go to another restaurant. For schools, you can't go anywhere else and you have to worry about consequences. Besides, I really like the teachers at my son's school. Since there is no process for parental input on curriculum or things that go on behind the veil, I would have to become a real pain in the ass to try and make changes. So what happens? parents smile and say that everything is fine, but then go out and hire a tutor.
KTM works to remove the veil (and sometimes the niceness factor) to try to get to the core of issues. In math, this means the details of mastery and the meaning of understanding. Things are happening at schools and parents have to pick up the pieces at home. These aren't always nice, happy, constructive discussions because they involve fundamental beliefs and assumptions.