Why don't you have a wife/girlfriend?

Vox at Alpha Games lists seven possible explanations as to Why you don't have a wife/girlfriend

1. You are too passive.

2. You overrate yourself.

3. You are too eager or desperate.

4. You pursue inappropriate women.

5. You're holding out for someone better.

6. You can't decide.

7. You're afraid things might go wrong.

Vox goes on to add meat to the bones of each of the seven points.

I can add an eighth possibility: you are too old!