The first reason we shoud not change the way we have done it is because its easier to maintain there is a system of ways to keep it running smothly , an example of how its runnyimg smothly "...the electoral college avoids the problem of elections in which no candidate receives a majority of the votes cast...there is no pressure pressure for off run elections when no canidate wins a majority of the votes cast...that pressure ,which whould gratly complicacate the presidential election process, is reduced by the electoral college , which invariably produces a clear winner...".[in source 3:in defences of the electoral college]

The second reason is how it has worked nicely for all of these years why change now.