I think the answer there is to tune the other bosses to a similar challenge level rather than nerf to get things lined up.
On wanting more people to be able to clear content - story mode was made for those who just want to see the content and mechanics and don't really want the maximum challenge. Hard mode is for those who like a challenge, at least on release. And Nightmare is for a select audience, those who want a true, nearly impossible challenge.
I'm of the understanding that a large amount of the former SWTOR player base left due to the lack of challenging raid content so I think nerfing is also a negative business decision.
Players did leave because the original raid content was in no way comparable of what you have today and not because a single mobs enrage timer was "nerfed" by 30 seconds.... . Any guild serious enough about what they are doing did attempt and kill the encounter/ cleared the operation. Nerfing an encounter is what happens in every MMO over time and if you wanted to face the "mathematical impossible" you have to try when it goes live for the first time.
At least we now know that the mathematic impossible can be beaten... thanks to that Bioware.