I have mod points, but I'd rather simply explain this...
Warren Buffet has actually made this exact analogy before (I believe when he and Bill Gates did a joint Q/A session). He acknowledges that he has no skills that would be of any use if he were on a deserted island. He's even joked that he'd be eaten in a couple of days if he were born while humans were still hunter-gatherers.
What many fail to understand is that there are positions in society. I'm not talking about peasant versus king positions. I'm talking about people who are particularly skilled in a certain area and they can take advantage of those skills to make a living for themselves and/or make others' lives easier. Farmers are necessary, soldiers are necessary, teachers are necessary, and investors are necessary (note, I'm using the term investor as define by Benjamin Graham), etc...
Why is manual labor considered morally superior to allocating one's money where it would do the most good? Why are those who pour hundreds or thousands of dollars into construction companies, mining companies, or wood/metalworking companies demonized for allowing companies in those sectors to expand their business, hire more people, and offer their product in larger markets?
Did the rich build this country? Of course not. However, without the rich, no-one else could afford to.
I would bet that the people who criticize the rich for having money are the same people who criticize those who finance expensive houses, a Mercedes-Benz, and Prada bags with debt for being irresponsible with their money.
Is being poor supposed to be the only moral way to live?