
Originally Posted by
Woggmer
Cases with like TBC, Wrath, and Cata they stopped doing World Bosses entirely and instead had "world bosses" in instanced areas. They stopped doing that in MoP when they brought back World Bosses.
It wasn't until WoD where they moved raids to be more like Seasons.. Season 1 being Raid 1# and then Raid 2# for Season 2 and so on. When they include additional raids in the same season (like Trial of Valor with the Nightspire, Crucible of the Storms with Battle for Dazar'alor) it leads to the complications of the loot tables.. where you have to pick between one raid or the other depending on the loot you want.
When MoP did the same thing it was more like Mogu'shan Vaults > Heroic Mogu'shan Vaults = Heart of Fear = Terrace of Endless Springs. (The later options dropping weapons that had a special socket for a legendary Sha gem you would get from the legendary cloak quest.) The armor pieces were the same aside from tier sets which you had to farm for valor to get from the vendor, with the only reason to do the different raids was to increase your chances at armor or trying to get a specific weapon and none of the bosses dropped any trinkets, it was totally RNG from the mobs themselves or from a vendor.
I can imagine that they moved away from this because of the complications and confusion it would cause for people trying to get specific gear or disappointment if the boss doesn't drop something that would actually benefit you.. like you've got a boss that drops armor but not good weapon drops.. or a boss that drops good weapons with skills to them but has no trinket drops.
I know my explanation of it seems very confusing, which is probably the exact reason why Blizzard doesn't do this anymore.. plus with Mythic+ giving more loot options like trinkets, weapons, necklaces and rings, there's almost no point to include more raids unless they want to make something very specific. Whereas with Raids all you need to do is get the tier set drops or a specific weapon/trinket drop.