How so? This is the argument that is repeated ad nauseum.
How would presidents solely be elected by large cities in a popular vote situation?
If more people in rural areas vote against the urban areas, then the rural areas don't win? Sure you'll have more voter turn out in certain places, but now there will be incentive for everyone to vote. Rural or urban. Texas or California. And so on and so forth.
1) I really think the EC existed to make the 'vote' not really a 'vote' in the old days. It was just there to give the masses something to do, and let them think they were legitimately participating. The original EC could take the public's vote into account but still ultimately had the power to cast their votes the way they wanted to. Maybe it was a protection against theocracy?
2) I think the modern incarnation of the EC are a political convenience to Presidential candidates. With the EC in place, certain parties just give up on certain states and don't even bother campaigning there. In other words, Obama came to Texas during his presidential campaign rarely just the same as McCain. The state was pretty much locked for McCain. Why would either candidate expend a lot of time and effort wooing Texas voters? Without the EC, both candidates would focus HARD on a state with such a massive amount of population.
So basically, you prefer a system which lets a few swing states pick the president in any election, whether they have the most people or not. You also prefer a system that makes it simply easier for the politicians to campaign.