Yeah and since you cant pick up special ammo with the icebreaker the nerf will destroy the weapon special ability at all making it a waste of exotic space
If they're going to increase the recharge time, they should add something to the weapon to make up for it. But as others have said, Bungie is essentially doing this to force upgrades to what will no doubt be even more powerful exotics in TTK.
They dug themselves into a hole with the etheric light upgrade system...what's the incentive to use new weapons when the old ones with great abilities can be upgraded? And once they realized what they had done, this was the inevitable result. It's not right, and I have no doubt that the expansion after TTK will feature nerfs to those weapons as well.
The cycle will go - New Exotics>New Content>Nerf Exotics>New Exotics - and so on. They think they've found a solution in this, but all it's done is anger the player base. Exotics should always be amazing and have unique abilities, all this does is cheapen them.
Part of the problem is also PVP, but as I stated earlier the only way to solve that is to force players to have a default loadout in a match with better weapons on the field - ala Halo. Keep your gear for the Trials and Iron Banner, use standard weapons in Crucible.
Or they could accept the fact that the PVP is and always has been garbage and just ignore it, but that's just my opinion.