I wholeheartedly agree. My latest winner had only gotten one single corruption in the entire game, after fully clearing two greater vaults and the entire final level. (I'm not counting the second corruption that I had gotten from playing with potions of raw chaos.) And he had a whole pile of items to deal with it, including not only SoCR, but also the potions from the ice queen and shrooms, as you say.
Thanks for submitting this RFE.