Why do men wear ties?

My busy day on Tuesday meant that it was late evening before I read a news site and discovered the Republicans had put on another episode of "Presidential Survivor." (This appropriate "debate" description via a communications prof named Patrick Stewart.)

I haven't paid any attention to anything any of these characters may have said; they aren't uttering anything but rubbish, so I don't have to.

But occasional pictures have left me with a nagging question: why do men wear ties? They trot out there in their dark suits uttering inanities and the sole differentiation between them is the color and perhaps fabric of their neck wear.

Actually it was the Donald who got me going on to this question. He not only wears ties: he favors shiny, solid color ones that probably are quite expensive but look to me merely slick and cheesy.
I tried asking the web my question, but Google and Wikipedia offered little help. Neckties are apparently the successor to a garment called the "cravat" but that doesn't explain the "why."

The most convincing answer I ran across was this:

... the cravat is the forefather of the present day tie. Men continue to wear one because they believe that it gives them an air of intelligence and authority far greater than they actually have. If a tie gets you the job, it says a lot about the people who hired you.