My thoughts as well. For that reason, I tend to value the T11 rankings (bar Sinestra/Nefarian) a lot more than T12 rankings, which for some reason can nearly always be cheesed for nearly every boss.
On t12, Shannox means multidotting, Baleroc is kinda okay but there's always the retarded countdown RNG which can screw amazing DPS parses, Alysrazor is cheesed by people tanking hatchlings/flying, Rhyolith is RNG lord (and depends on whether you're AoE'ing, dps'ing Sparks, or the legs?), Domo depends too much on guild strategy (how many cat leaps = how many cats you can cleave down), Ragnaros can be fucking RNG as hell (depending on trap location, whether you can always melee the boss while staying in breadth or not, parryRNG in phase 2, whether you are on taunt duty for traps if you 1-tank it, deluge, etc).
All in all I thought Omnotron, V&T, and Cho'gall to be perfect encounters for WoL rankings, and they haven't been topped in Cataclysm. But hey, to each his own.