In 1.6 there was a UHC mode added, this means that your health doesn't regenerate normally, it takes either a golden apple or a potion to heal you. On the server you can select between easy, normal and hard difficulty, so I think there should be an option to enable UHC mode for yourself. If some people want to engage in UHC mode they are welcome to, but if you don't, you don't have to.
I personally think it adds a new level of difficulty to the game, which some people want.