Getting frusterated with non-payments.

I have bought and sold from ebay for years, but just in the past few months I have noticed a dramatic increase of non-paying buyers. I get so frusterated with this, so much that when I see a buyer having 20 stars or less I automatically know they probably won't pay and I don't want to discriminate against all newer ebay accounts but I am just sick and tired of having something sell, then having to re-list because the buyer never pays and never messages me back. I have noticed that these types of buyers mostly have between 5 to 20 stars, but the most common number is 11. Has anyone else noticed this? Why isn't Ebay doing something about it? Most of their money comes from us sellers and I'm just about done with selling over Ebay.