If I'm starting a new hobby or wanted to buy a present for someone with different interests, I would be very annoyed if results were hidden from me because of a name clash with a product from my purchase history.

A good product search isn't personalized, and doesn't try to predict what I want. It just shows the results in a sensible manner, and lets me use categories and keywords (in addition to user reviews, price, availability, etcetera) to filter the results.