They could have gone a step further and allowed us to get an item that added the 'proc' you desire to whichever cloak you wanted to use. For example, what if you wanted to be able to use a dps cloak with a healing or tanking effect? It would have led to some interesting combinations and gear choices, as opposed to static effects which will inevitably have content designed to compensate for.
I really wish there was more creativity, I liked the idea that Thunderfury debuffed a target in such a way that it would make certain fights easier. They didn't have to balance every boss fight in the game around the assumption that you had this debuff, but having that item in the raid could mean a meaningful difference.
I suppose that raid design is now shackled to balancing the heck out of everything around the pve progression race, which is quite stupid because things really shouldn't be balanced around the top 1% of the top 1% downing everything in the first 3 lockouts.