Granted, they silence one who repeats: "We give thanks, we give thanks," because it appears like she is recognizing two authorities. And granted that they also silence one who says: "May Your name be mentioned with the good," as clearly she is thanking God only for the good and not for the bad, and we learned: One is required to bless God for the bad just as he blesses God for the good.
However, in the case of one who recites: Just as Your mercy is extended to a bird’s nest, why do they silence her?
Two amora’im in the West disputed this question; Rabbi Yosei bar Avin and Rabbi Yosei bar Zevida; one said it is because it engenders jealousy among God’s creations. And one said it is because she transforms the ways of the Holy Blessed One into expressions of mercy, when they are nothing but decrees.