The variance is low, but that shouldn't distract from how it's a Gurmag Angler with 2x the cost if you have other relevant removal targets (it's particularly funny if you have both it and Angler in play). Waker of Waves should easily win the game if you overwhelm their unconditional removal suite (which is rarely that large) with threat density / counterspells / reanimation / taking it in draft / them being in the wrong colours, but in my experience Striped Riverwinder needs the game to be basically already won to start attacking.
The purpose of a control deck is to control the board. It doesn't mean the control deck has won already if the board on the opponent's side is empty or almost empty. And the nature of control decks is that they don't have a lot of other relevant removal targets, maybe even none at all. I would never consider a finisher without resilience for a control deck, not in my cube at least.
For reanimator it's even more important to have resilience unless the creature can end the game with a single attack (like Artisan of Kozilek). Reanimator decks only run 4-5 reanimation targets at best, if your opponent can simply cast Go for the Throat to remove them without any effect it's a card that has no business in such a deck.
The only deck where the whale is possibly (slightly) better than Riverwinder would be ramp, but since it's a blue card it's not a reason to run it from my pov.
The purpose of a control deck is to control the board. It doesn't mean the control deck has won already if the board on the opponent's side is empty or almost empty. And the nature of control decks is that they don't have a lot of other relevant removal targets, maybe even none at all. I would never consider a finisher without resilience for a control deck, not in my cube at least.
For reanimator it's even more important to have resilience unless the creature can end the game with a single attack (like Artisan of Kozilek). Reanimator decks only run 4-5 reanimation targets at best, if your opponent can simply cast Go for the Throat to remove them without any effect it's a card that has no business in such a deck.
The only deck where the whale is possibly (slightly) better than Riverwinder would be ramp, but since it's a blue card it's not a reason to run it from my pov.
My Old School Battlebox
My Premodern Battlebox