Where is this idea that sociology can't be quantitative coming from?
Have any of the ignorami making this claim even looked at a sociology paper published in the last thirty years?
Any social science can and must be statistical or have some way to show evidence for its claim. Things you can't prove is called faith.
Austrian economics just makes a distinction between economic theory and economic history. Rational thought experimentation is the only thing needed to formulate sound economic theory. You can then compare that theory against the statistical record, and if they don't match either the statistics are the outcome of other factors or your reasoning was flawed somehow. But, if your reasoning is correct, it's impossible for your theory to be wrong.