The popular vote represents the will of the major urban population centers.
Doing away with the EC would be a fast way to civil war. Which states benefit from the EC? The food and natural resource producing states. Which states depend on the food and natural resource producing states? The ones that would benefit from the popular vote. Do away with the EC and what would happen? The very next election cycle, every candidate would only go to the major cities and promise the moon, totally ignoring everyone else. The less populated states (which have the guns), seeing that they no longer have a voice, would use the only club they have and all of a sudden, the major cities would see food and product prices go through the roof and supplies shrink. Then the guns come out, because the only recourse at that point would be nationalizing food production. USSR, here we come. No, much better to keep the EC right where it is.