That's right - I hadn't thought about the larger number of hearts today versus back then. Physical weapons just dealt more damage in previous Metroidvanias. Special attacks are pretty devastating in OoE, but they also take a LOT more hearts - really the equivalent of item crashes. It takes longer to fill them up too unless you've got the heart gear equipped. On the other hand, if you made the weapons use less hearts, then it would be easier to collect hearts and make those devastating attacks. Sounds like a bit of a balance issue...
and also, i'll add this...
in the early castlevania series no other person in the castles we're included, remember when playing castlevania on SNES no shops was invented, meaning that you have to finish the game using whip and a ton of projectile weapons, also, golds back then we're points and doesn't much be found on candles, now in replace of hearts from where shops in castlevania arrived, the golds we're now stored in candles, so it's not hard for you to collect money while seeing candles as well...
(maybe belmonts doesn't know how to buy stuff

)
Also, couldn't you completely fill your hearts in other games by going to a save point? (I know you can't do that in SotN...).
yeah before i know it could be done, but usually it really doesn't so the best way is to find a candle that is near a save point and fill up, at OoE you really have to go to the village in order to refill up immediately for emergencies...