RSRH:
If I understand correctly, your point is that we should engage them in halachic debate and prove them wrong, instead of just calling them what they are.
Now, firstly I disagree with that. I think that engaging them in debate legitimizes them. The same way we don’t debate the church, or the talmud professors in the universities, or the conservative, we shouldn’t be debating these kookoos either. (Referring to YCT, and co.)
But secondly, I happen to disagree with you about how we have been acting towards them. For the most part, chareidi judaism has been ignoring them, and considering them a non-entity, and something of a joke. Which I happen to think is the best reaction.
The only place you see this discussed is on the internet, and mostly by right wing MO.