That is interesting - but why wouldn't they use it? (Showing my ignorance) :D
However, this is that "randomness" I was talking about the other week in a post with some of the cards - there are new dynamics everywhere. If the older great players don't adapt, they won't survive as the new players ramp-up fast.
Kraken is a 12 Mana card.
In a 30 mana battle with Kitty (7), that leave only 11 mana for 5 cards. Very few people will go with that.
Ah - I have never played with a Kraken and I am terrible with Kitty!