Food/Water actually becomes extremely powerful without hardcore mode too, if you have high survival. Stack different foodsorts together at once, and you have a ridiculous heal over time effect going. Sure, Doctor's bags get useless, and so does Hydra for the most part, but the rest still retain high usefulness if you have the right build.
And when I speak of inventory management, I'm mostly talking about weight. It's simply not fun for me to play this game with hardcore mode on, having to micromanage the inventory so much. I do like the concept, but the execution was a bit sub-par, since it just didn't add any challenge to me. Just tedium. It wasn't harder to dedicate a certain amount of carrying capacity to water and food. It wasn't hard to keep H2O, Food and Sleep meters zeroed out. It didn't cost me any more caps, or lose me any income, since I wouldn't be picking those things up anyway if I wasn't in Hardcore mode. All it did was add more trips to the vendors since I couldn't bring quite as much loot at once besides my 'need' items, and add some more buttons to push every once in a while.
I can definitely see why people like it... I just don't like it myself.
Now, if there'd been a challenge mode which removed two thirds of the water and food sources, and made beds/sleeping places much much more rare... then I'd turn it on and enjoy it immensely. I guess what I'm saying is that I expected the game to get harder with hardcore mode. It didn't, for the most part. Just made it more work.