So the outlying areas are given slightly more say in selecting the President than the high density areas because otherwise they would end up with no say at all.
If the election was based solely on popular vote then most of the nation could safely be ignored. That translates into actual policies. Trump won among people who feel that governmental policies are already against them. The elimination of coal mining and the off-shoring of manufacturing were both caused, at least partially, by environmental concerns of city dwellers who are unaffected by these policies. Similarly, a huge hike in the minimum wage an be absorbed much easier in large cities where the cost of living (and therefore the median wage) is already higher than in outlying areas where such an increase would cause major unemployment.
Because of the rise of highly dense cities, the original concern is even more relevant. There are more than 3,000 counties (and equivalents) in the US but half of the population resides in just 15. This correlates to votes for Hillary Clinton vs Donald Trump as shown in the graphic below.
The fear was that a few large states would trample the smaller states by constantly choosing a chief executive who only represented their interests. The small states were given a slight advantage in order to be sure that their concerns were also addressed.
Disparity of population goes back all the way to the convention when the Constitution was first written. Small states wanted an equal voice in the federation. Large states demanded more power. The eventual compromise was two houses of Congress, one that gave proportional representation to the states and the other that gave equal voice to them. At the same time, the Electoral Collage was created with states getting electors for each member of Congress. This gave the small states a slightly larger voice in selecting the president.
There is a lot of frustration right now because Hillary Clinton won the popular vote but Donald Trump won the Electoral College. There are also complaints that every state gets to elect two Senators regardless of size and that even members of the House of Representatives represent different numbers of voters.This is not a bug, it is a feature and it is working exactly as intended when the Constitution was written. In fact, this disparity in representation is more vital not than ever.