In 9 Money Rules to Live By [sic], Liz Pulliam Weston stated, "The average graduate makes 70% more over his or her lifetime than someone who stops with a high school diploma."

Without elaborating on the details of the survey or research, this statement implies that going to college will bump up your lifetime income by 70+%.  This may or may not be the case, due to several confounding factors.  There may be a high correlation between college and greater lifetime income, but there are correlations between going to college and several other statistics, like race and socioeconomic status, for instance.  During college, I spent 3 years giving tours and talking with prospective freshmen.  One thing that struck me was that not all of the prospectives would be best served by my alma mater, or even college for that matter. 

It is unfortunate that we, as Americans, are wearing blinders and declaring that college is the right answer for everyone.  Some need the discipline of the military, some the immediate financial benefits of a post-high school career, and some simply don't have the intellectual capacity for a college education.  It's not right to encourage people to do things that would be to their detriment, and your blanket statement about college improving someone's financial outlook does just that.