Cancer should only be used for decks that use shitty, annoying deathrattle minions not slower control decks.
ie. You kill them but they keep coming back.
That's why Reno Jackson is now nicknamed Chemo Jackson.
Fatigue decks are just as cancerous imo. The fatigue state should be used in order to break some kind of stalemate or tie. Making it a win condition is awful. I think it is stupid and brainless when games get decided in five or six turns, but the other side of being intentionally dragged out into a 35 turn game is annoying as hell and not fun.
Arena actually feels like where the pace of the game should actually be. It's slow enough that there is serious consideration for having big drops but fast enough that you don't get dragged through tar pits.
People are high on Reno Jackson right now but personally it's not the type of anti-aggro design I particularly favor because it benefits fatigue decks and makes them more efficient then ever. That is not just anti-aggro design it is also anti-control design. Card design like Zombie Chow is far more interesting and beneficial to the health of the game as a whole.