Why the fuck are you guys even hung up at all on healing? The healing feature of save points is what broke Metroidvanias. Just grind away, grind grind grind until you're a high enough level or your souls are powered up enough or you have enough potions or you get that epic armor you were killing the same damned enemy hundreds of times for. A one-time save is just fine. "You beat the boss! Congrats! Now heal up, record your progress and continue on!" You don't need to save the game every 5 fucking minutes. You wouldn't even need passwords because it would be the exact same as with passwords. And even with backtracking, you shouldn't need to save. You've beaten that area once already, so why would you need to save the game before going through it again? You already know where everything is, so if you have any ounce of skill at all you should be able to traverse that area backwards with little difficulty especially now that you received an upgrade from the boss. And yes, I have played Metroidvanias. I have four (well, 3.5, because I don't really think of LOI as a full Metroidvania). They're my least favorite games of the series (well, not counting the N64 ones but that probably had to do with trying to play on an emulator with a keyboard instead of a gamepad).
Seriously, people need to learn how to fucking play a platformer again. Dawn of Sorrow/Aria of Sorrow were not platformers. Order Of Ecclesia wasn't a platformer. Those were all cakewalks. You jump from one slice of cake to another slice of cake, and if you mess up you plop down into a glob of frosting. Metroidvanias are just side-scrolling RPGs with formulaic construct and gameplay riddled with design flaws. Playing through them is a chore; there's no sense of accomplishment, you just want to go play something else when you finally beat Dracula so you can feel like you actually played a game before the day's over.
Castlevania needs to make your palms sweat. It needs to make rooms full of spikes and swinging blades make you think, "How the fuck am I supposed to get through that?!" I'm not saying Konami needs to ramp up the difficulty to Ghouls'n'Ghosts level, but who really cares about alienating newbies? Why the fuck do newbies even matter? How the hell would a newbie even know the game is too hard? So what if it's hard? Did the newbie buy it? Then you got your money! If it's beatable, IGN will give your game an honest review and people -- newbies and skilled gamers alike -- will buy your game. And since professional game reviewers seem to never even discuss game difficulty anymore, I doubt a hard game would really be an aversion.
Then there's the issue of easy/babysitter/cakewalk games being a horrible business strategy. I beat Lego Lord of the Rings and sold it back to GameStop. I beat Order Of Ecclesia but still have it. What's the difference (other than one cost me $15 and the other cost me $40)? LEGO just dragged me around on a leash, whereas OOE at least gave me some steady challenge throughout and thus has some replayability. As a game developer, you want people to be ABLE to beat your game, but you don't want them to beat it easily. If people can beat your game easily because you pad it with safety harnesses throughout, your game will be stuck in a warehouse because the same 3000 copies of it will be resold over and over at GameStop.