This is a rule specific to ninjutsu
The metagame morphing into this is not too surprising since Treasure Cruise, from a deck design perspective, incentivized people to play either tempo or blue midrange, decks that dont really care about specific cards, and love having something like a one mana draw three to refill their hands (and subsequently, the graveyard again and again)
Perhaps you can find some underpriced copies, maybe even below buylist
With Chandra, Torch of Defiance giving a large boost to red decks, we could see direct damage rising in popularity as a way to close out games
Robot or human
It's not gonna feel amazing on two or 5, but it can do both serviceably, and that's a big deal