Bungie doesn't nerf weapons for no reason or as a way to say fūck you to the community. They do it so their game plays as its meant to, and mechanics actually have time to take place (*cough* *cough* gjallarhorn). Everyone complains about thorn and last word, they need nerfs. The AI doesn't complain because well it's a computer, but it's the same story: the gjallarhorn and to a lesser extent the Icebreaker are too good. TL;DR Datto sums it up well, skip to 18:50 for the overall message