Mostly I just like the look of it, and it's something different from the norm. I think it likely needs to change - but not to hearts.
I think if I did hearts for health, coins for currency, and treasure chests for random things scattered around the map, I'd end up with a game just like any other. The worldfeel is the most unique part of the game, so whatever I do has to move that needle in the right direction, generally away from classic/tropey iconography.