The only reason why the electoral college even exists is because it is the status quo. If America had gained independence today, or in the last hundred years for that matter, we probably would have gone with the popular vote.
The electoral college does make elections more fun, but it ultimately serves no distinct purpose anymore (if it ever even did)
In part the original concerns that created the EC still exist today. It reflects the nature of the country as a union of sovereign states.It may symbolically "reflect" it, but how is it actually relevant to federalism? I see no reason why popular vote would be any more or less likely to undermine state authority.
I don't see why this is a plus when the "proportionality" in question is introducing some of the extreme disproportionality of the Senate into the equation.
Has there ever been a Presidential candidate, nominated or not, who was in such a situation? In any case this seems more like a bug than a feature. You could frame the exact same issue differently: "the popular vote prevents someone deeply unpopular in certain regions from winning with narrow support across the rest of the country". That's what Lincoln did, and while we tend to approve of the result in hindsight because we agree with Lincoln's cause, one could easily imagine a candidate winning Lincoln-style on a cause we disapproved of, while still resulting in similar frictions.
In any case it only matters when voters are highly parochial. If people's identities are not overwhelmingly tied to their region, then there is no particular reason we should worry about a candidate winning with a certain geographic coalition than say, a particular economic or particular racial coalition. Is it a problem that Obama won despite losing whites, the majority racial group, by winning minorities by huge margins? I don't see what would make that so much better than Obama losing most states by small margins and winning a few by huge margins.
And in any case, why should this logic be limited solely to the Presidential level? Surely it scales down. Should Illinois have an "Electoral College" that would prevent Cook County from "overwhelming" the rest of the state?
The House of Representatives is by far the closest element to a Westminster Parliament.