Elves are fictional creatures. They don't have to adhere to a rigid standard based on tradition. New traditions get created all the time. D&D is flexible when it comes to ensuring the best player experience. There's nothing wrong with wanting to be able to identify with the character you play by having it resemble you--that's why we have character creators.
Having greater diversity that reflects real world diversity hurts no-one and can dramatically improve the experience of people who have long been told they don't look like the "standard."
This is fantasy--logic need not apply.
(But if we do want to apply some real world logic to it, remember that human genetic diversity is actually very small compared to most other creatures. Given that D&D races are different species, it may be reasonable to assume they would actually have greater levels of genetic diversity than humans and, therefore, some may coincidentally resemble different human races given that they are all humanoid and our brains are wired to recognize the familiar.)
Sliders, headparts, and a bigger sampling of presets would give people a greater range to shape their experience however they want it.