Are you talking about a Hardcore mode for levelling from 1-50 or a general Hardcore mode? For levelling I could imagine it to be a challenge but for the entire character and it's lifetime...won't work for this Game. While learning the fights, dying is unavoidable. And even if you are the best player on Earth, another one failing in a Primal/Coil group leads to your very own Death as well so it is no good option imo.

But I do like the idea to level my char this way to 50. And it should be doable. You have to take care that your equip is always on par and have to watch every step. Titan Story mode will make your heart beat finally again. :xd I would even level an alt like that if this option was given.