Valor upgrades only sucked when going back to the vendor really - so if the valor upgrade could be a drop off bosses and however many could be used to upgrade a piece of loot as a guarenteed drop it gets rid the rng drops of titanforging while keeping the convenience of not having to go back to town to fiddle with gear you just got.
Stockpiling for upgrades you later get is a concern (could be exclusive to tier or valor reset per tier as it did before) - especially as people save for BiS, which titanforging got around. "Ideal upgrading" could be negative in terms of not being able to spend on what you have because you "need" to save for BiS upgrades. Knowing what to spend on can also be comforting, bit rng drops could also be good so it's subjective. (Think SoO did titan/thunder/warforging power and drops best.)
Corruption just wasn't fun sans only secondary boosts to make rotations more involved with more haste, basically. Being cursed wasn't fun, only punishing, not very minigamey except on some specs with multiple ways to immune the effects - but that is negative when such abilities are required for soak jobs.