Mike is correct - the term has nothing to do with anatomical parts and refers only to that area of the subject (be it body, tree, clothing, etc.) where two members come together. If one becomes offended by "crotch", that may just be a reflection on their level of knowledge regarding the term.
Back to the point, why feel compelled to call it anything other than highly figured wood. The wood used by Brian in his bowls does not appear to me to have the characteristic feather associated with crotch wood, and while it may have come from that area of the tree, perhaps the angle of cut did not preserve the figured portion of the wood - or, perhaps I am just not observing it well enough.
Most have opined and it would be best if we kind of leave this topic before the conversation takes a bad turn. Thanks.