But it wasn't really playable and that's only 5 mana. You're talking 8 mana in a faster meta. You might need ~2 turns to make up the loss of tempo and I think that's problematic.
+ everyone is running Ooze/Harrison and now they'll just save it against weaponless classes instead of playing it for the body alone.
The difference between a 0/6 and a 7/7 body is massive though. And the fact that the effect is guaranteed to still go off, even if you deal with the much bigger body, is what makes Medivh a lot better than Stone.
As for the weapon counter tech cards, I just went through vS's latest Data Report and exactly ONE deck out of the 26 they had listed was running Ooze or Harrison (Renolock). So saying everyone is running those cards is hyperbole, to say the least.