When people are asked why they are single, one major response is "I've not met someone"

While that sounds true, it's not really factual because people who fit your bill are always available if you can identify what you want.

Let's assume your spec is so rare that only one exists in every one million humans, you still have 8,000 options to choose from.

So, is this really a lack of 'who' or an inability to articulate the 'what' you expect from this person?