Is it justified to share broker's commission with the buyer?

I was just told by a new broker friend that she is proud of her success in business of over 40 years even though she had to share her commission to buyers especially in big ticket deals. She justifies this practice by the result: success in closing most of her deals and her ability to share her commission to her less fortunate agents. "Everybody happy" she says.

In another case, I was encouraged by a developer to share my commission to a buyer because the only remaining issue in closing the sale is the price.

Is this practice justified?