The problem with this was that players could, for example, trigger a Werewolf by playing no spells that turn and then, when the trigger was on the stack, play instants
Oh, also, if it goes into your graveyard from anywhere it instantly gets shuffled back into your deck
It must be something that it could legally enchant, but not necessarily something it could target if it were on the stack
We've certainly noticed a surge of interest in Warhammer 40k around the release of the game, so it's not inconceivable that that's translated to more players building around one of its characters
Check out the transforming Gwen Stacy/Ghost-Spider card
Crystalline Sliver outright nullifies all targeted removal along with a number of other solutions