Personally, I think the whole "Exotics should always be better than all legendaries" thing is true. However, only in PvE based activities. That's why they need to make it a priority in this next DLC and Destiny 2 to completely separate the two sandboxes. Something being nerfed because of overpowered issues in PvP shouldn't change how it performs in PvE at all unless it's too good in there too.