Answer:
Dissatisfied customers produce more than twice as much word-of-mouth as satisfied customers do.
Gregors logic is flawed because because unsatisfied customers tend to stay angry at the product and indulges to communicate more regarding the product as the satisfied customer would. This in a way would be a negative promotion of the companys' products at a higher and faster rate.
Therefore his logic that he is reducing positive feedback even from the negative customer falls flat and is flawed.