On A Bad Argument for the Knowledge Norm

It's pretty common to hear people defend the Knowledge Norm by citing examples of people criticize others by saying "How do you know that?” I want to give three rebuttals to this kind of argument.

1. People routinely say, in the same kind of criticism or challenge “How can you be sure of that?” or “What makes you say that?” So by the line of reasoning above, *certainty* is sometimes the norm. The latter is request for evidential grounds which seems to seek merely sufficiency of evidence. So the *whole* range of such challenges seems to support the thesis of my paper: "Knowledge and Context Sensitive Norms: A Defense of Simple Moderate Invariantism" recently updated on my philosophy page.

2. Before long it will be impossible to ignore the fact that non-factive uses of cognates of "knows" are plentiful and can't be so easily cast aside. Either there is a solid way of explaining these away (not the casual one we usually encounter) or there isn't. If there is, I see no barrier in using it to explain away casual uses of "know" in "How do you know that?" If there isn't, then using the same standards as we’d have knowledge as non-factive, etc. The missing arguments for the analogy would need to be supplied of course, but I don't think that would be too much trouble.

3. Suppose I make an assertion and someone says "Well how do you know that?" I'd just say "Well maybe I *don't* know it, but I've got good evidence that it's the case and that's all I care about."

a. There are good pragmatic explanations as to why we don't hear this kind of speech much, so no need for fancy semantics of "knows".

b. I just don't see how I'm subject to ANY kind of criticism here (besides maybe disrupting polite society, but then again I'm not sure that even counts (it sure doesn't count much to me!)).