People love to play cards like Prison of Yogg Saron. However, after the last couple expansions we are getting too many results such as Wheel of Death or Announce Darkness. As funny as it may be, the gameplay is completely ruined when these effects go off. Rarely is it a good thing. Stress would be relieved if certain outcomes were either impossible or extremely rare.
Because the card is a “last hurrah”. It’s not mean to be good. The Titan yogg is not good because of those random nonsenses but because it can control minions and make them fight each other (hell even the cards are better).
Maybe HS isn’t meant to be good. Have a fun card? Let’s make it unplayable. Great idea!
If you want that card to cast only helpful spells, it would cost at least 10 mana.
It’s a neutral and spells are often more powerful than minions.