That's not a great one, Nintendo started out as a playing card company after all. Where you start is quite irrelevant. It's where you end up that matters, and I think MtGox demonstrates that quite clearly.
I don't hold MtGox's origins against them (plus I'm a MtG fan).
But Nintendo didn't pivot from playing cards to guarded stagecoaches, they stayed in the entertainment focus and evolved over a century into electronics. The stakes were always low.
Pretty low bar honestly, even if they had pivoted to stagecoaches it’s hard to knock them if they’d been successful. The ends are more important. Gox was really stupid though.