Elector, vote for me...

Here's a defense or explanation of the electoral college that I don't often hear : "to avoid the dominance of urban electorates and those of very populous states such as New York and California at the expense of smaller communities". But I thought that that was the whole point of a democracy, that the result is "dominated" by large groups of people, namely the majority. So instead, the 'majority' of voters are ignored for the benefit of the small communities (read minority). Can someone please explain to me why this is a good thing? Please?