I kind of agree. Genn and Baku decks ranged from tier 1 to 4 just like anything else. Multiple classes had Odd/Even and Standard variants that all performed well.
Druids weren’t using Genn or Baku, and Malygos Druid was probably the best deck in the game at high level for a lot of Year of the Raven, while other variants were also very strong.
Hunter had an Odd face variant but the premium decks were standard midrange lists with Deathstalker Rexxar.
Big Spell Mage and Secret Mage didn’t run either, and Odd Mage didn’t become a playable deck until Rastakhan’s Rumble when it got the 7 mana 4/4 summon Ragnaros guy.
Paladin was the main advocate of Genn/Baku with both having viable builds, and wasn’t doing a great deal without them until RR, when Shirvallah created that OTK.
Priest had dedicated Odd cards but none of it ever saw play. I can’t even remember what Priest was doing during Year of the Raven, probably some toxic Divine Spirit/Inner Fire or Velan/Mind Blast garbage.
Rogue had its Odd aggro build, which was pretty nuts but also had standard lists with Caverns Below or Kingsbane.
Shaman had a very strong Even deck but also had Shudderwock, which was strong at high ranks and didn’t run either Genn or Baku.
Even Warlock was a really solid deck, but so were Zoo, Cubelock and Control Warlock, none of which ran Genn or Baku.
Odd Warrior was mega over hyped until The Boomsday Project and even then, Control Warrior was better after Rise of Shadows (I think Genn/Baku were axed by then). Quest Warrior had Odd and Standard versions but the Standard version was generally better.
Tl;dr - Odd/Even decks were pretty much on par with standard decks. I think they rotated Genn and Baku early because they interfered with future card design rather than because they were too powerful.