Commissions should be lowered by the market. Many realtors will refuse to show houses to buyers where they don't make 3% on their end. Maybe that's not morally right, but if their commissions are cut, it could push many of the big volume deal-making agents into other fields.
The point of the article is that the market is not setting the commission rates. The commission rates are being protected by real estate commissions and misguided laws. Remove those protections and the market will find its way.