I know there is an obligation to design cards that have cool effects and that are flashy, but the game has been out for over 10 years and the team should know when certain card designs are problematic.
Take Murmur for example. How else did they expect this card to be used? The only thing it does is cheat insane mana and create blow out boards. Why print a card like this when its only purpose is to scam through mana cheat? It really doesnt matter what the power level is for cards like these 6 mana 7 mana who cares? There is no reason to have an effect that feels terrible to play against. If you cant clear the scam board, you lose. If you can, you probably win but it doesnt feel good because your opponent’s strategy revolved around blowing you out and hoping you couldn’t stop it.
If a card screams blatant exploit just by the nature of its effect, dont make that card. This seems like an issue that is easily avoided.
There are plenty examples of cards like this. Zarimi, oakheart… you could go on for days. Why do these cards exist when all they are ever used for is scam strategies?
Its hard to have an interesting back and forth or gain incremental advantage over several turns with these kinds of designs. If you make a busted card, people will abuse it, no matter what the intention for the card was