> You are refuting the validity of a number of fields if you don't accept them as sciences.

It's refuting their validity as sciences. Science is often taken as more authoritative and objective as other subjects, so the label matters.

I may be a perfectly good dentist, the fact I am not a neuro-surgeon doesn't invalidate my worth as a dentist;

But If I claimed to be a neuro-surgeon I should be investigated before I cut open any skulls.