Because the fictional basis in which I imagine my DnD games isn't even LotR it's from the many video games and comic books where and anime where stuff like flash stepping is just part and parcial of combat training. Hell, even something as basic like a whirlwind attack is either stuck to one subclass or made a spell.
And if I had my way, they can have that kind of fighter too--just don't use any of the cool naughty word I like, use basic attacks and never try to be anything better than Just Some Guy(IRL+) while I get to do flash steps.