I know it artifically increases replay value.
I think hard mode, if it's possible to beat it in, should be allowed at the start.
But honestly, after you beat a game, I don't think it's necessary for there to be any reward for beating it. It should just end. If you're not satisfied with a game after it's beaten one play through... then that game failed imo. Yes, extra difficulties challenges seem tacked on, or at times are neat. But there are much worse design decisions that developers make than this.







