Why no buyer brokers in commercial real estate transactions?

[Aaron Xie]

I just found out that more than 80% of commercial real estate transactions have no buyer brokers. That means buyers are not represented or protected in commercial transactions! 

Is there a reason for that? Is it because the buyer broker won't be paid a commission, so no one is willing to represent the buyer? 

I know that in commercial real estate transactions, the listing broker is entitled to a commission of 6%, but will that be shared with a buyer broker?