I guess there are two sides to every coin. I know I've heard plenty of people say similar things about grad school. I don't intend to be rich during the next 5 years, but based on my monthly living expenses and my monthly stipend, I should be fairly comfortable...and I even turned down better money from another university.
Even after 4 years of college, I still don't know "what I want to be when I grow up", but I do know that I love research. Grad school will allow me to continue doing what I love, while trying my hand at a few new things, all the while allowing me to get a better grasp on what I may want to do when I finish.