Because most domainers are buying the wrong domains.
Be assured that the investors that buy the right domains have more than 1% sales.
So, if the industry is composed of only five domainers who have 100 domains each, and one of them sells five names, the stat for the industry is 1%, but it is 5% for the successful domainer.
The 1% stat does not reflect the fact that a few are doing it right and the majority are doing it wrong.
The 1% stats don't reflect the pricing element. You may have 100 premium names listed everywhere, priced at 10 million each. By pricing them so high and not selling a single name, you are affecting the stats.
So the point is you might be indeed choosing the right names, but the wrong price.
Choosing the right names is extremely important, but even that is only part of the game. Where you list them, who you contact, how you price them, how you negotiate, etc., are also very crucial matters.