Well lots of people find it useful , and also his healthbar changes colors depending on how damaged you are.
Pretty sure the default one had something like this.
Would be useful considering there is default dm gamemodes.
I forgot why it got removed, I think it was about something with younger players or something... but I don't see a reason we shouldn't have one, many games have healthbars, even Roblox has a healthbar and they have players as young as 4 years old.
It was removed because it invokes players to do very annoying things. For example, running away in fear just to die by an undeserving player. I've noticed this in any game with a healthbar. People run away at low health, and then I lose the kill completely, and the guy gained nothing out of running.