Dr. Craig is a liar.

[Angrboda]

Is the importance of falsifiability really being questioned?

The problem is that the proposition "falsifiability is important" is not itself a falsifiable proposition. The criterion of falsifiability is justified on philosophical grounds which, themselves, are not falsifiable. It's a point about the self refuting nature of any propositions like "in order for a proposition to be considered true, it must be falsifiable." Falsifiability itself fails this test.