[Before we get started, check out this historical overview from the LA Times' Mark Z. Barabak.]
There was a point decades ago when the Iowa caucus and the New Hampshire primary actually served a useful purpose as search committees, allowing candidates with little name recognition and limited budgets to make their case to a small politically engaged state. This is what happened with Jimmy Carter. To a degree, it also happened to Barack Obama though he was hardly as obscure as Carter. I don't remember if the following was something I said or if it was said to me but after his speech at the democratic national convention in 2004, one of us told the other that we had just seen the man who would be the first black president of the United States.
That one scenario where someone most people have never heard of manages to come in first or second is the only time that the results from Iowa are important or newsworthy or even interesting. That is the entire case for Iowa and to a degree in New Hampshire going first and it has largely evaporated in the age of mega budgets and the long campaign.
Take take it away and Iowa becomes the Golden Globes of American politics, everyone knows it's absolutely meaningless but does come first and all the journalists covering the real story are starved for something to talk about.