Most secrets by design are fair as they require the other player to make them work. Bamboozle fits in that design very well. Because you, the opponent, attack the minion, you get to decide which minion gets evolved. On top of that, testing for secrets in rogue right now is very easy as there is only 3 in standard. It’s not like hunter or mage where you have to test their full library of them. With there only being 3, it makes sense that the EPIC one would be powerful or have such a unique effect as the other two are strong in their own rights.
tl:dr rogue secrets need to be powerful right now for the archetype to survive.
when more are printed in the same format pool, then I’ll see cause for a nerf