I suspect that in years to come there will turn out to be some genetic basis for the 'collecting' gene, and a reason why it was a useful characteristic for early humans. Close studying, making fine distinctions between 'good' to be hoarded and 'bad' to be avoided might relate to which plants were edible vs poisonous. You think?

Anyway, we have to admit that OCD style collecting--of anything--can be a practical problem and not good for personal relationships. Even something as benign as too many musical instruments around the house can get in the way of intimacy. On the other hand, having a big organ is not a problem and can even be helpful.