Right... because America was built on the backs of the enlightened and educated

At some point, probably at the same time other countries started to emerge as world powers, we lost our way under the guise of "do less.... think MOAR"
We need less labor saving devices and more.... labor.
America like the rest of the world was built on the backs of the underprivileged, underpaid, hard working immigrants... oh yeah and those slaves (ie cheap labor). The problem we face today is a global economy. No one is going to hire Joe and Mary when it is cheaper to manufacture something in China or wherever the next low paying workforce might be. The America that you so fondly remember never really existed. The roaring 50s were wonderful if you were a white male, not so much so for anyone else but I digress. My point is that an educated workforce is better able to face the challenges of a global economy.
Now remember if one enters the work force at 18 that is 4-5 years of extra earning. In reality they could be $200,000 ahead before a college graduate even accepts a job when you factor the 4-5 years of loss wages while enrolled in college and the 4-5 years of debt accumulation that a college student will face. So if a college graduate is making for example $20,000 more a year it would take at least 10 years of earning (we're at 33 years old + now) before they break even with the person that skipped college and that's assuming they aren't accruing interest on their student loans (and we know how likely that is......).
I would buy your argument if I believed for a second that the avg high school grad was capable of saving $200K over 4-5 years. Do they not have to pay taxes? Rent? Or other living expenses? And last but not least are they not prone to credit card debt?
My dad is an electrician and last I checked he never mentioned a shortage of them. This idea that our workforce is need of more electricians, plumbers, mechanics etc is a total myth. Furthermore, an individual who wants to pursue a career in one of these fields has to complete an apprenticeship prior to obtaining a license. Depending on state licensing laws an apprenticeship can last anywhere from 5-7 years. Oh year while training they're not making $40K-$50K a year. However, once licensed they do earn a very good living. Especially if they own their own business.
The problem is we're shoving the perception of "college is 4 every1" down the throat of every single youth in this country and that just isn't true. People use to know what they wanted to do before going to college and now we have kids 3 years in without an idea (or care) in the world.
You do realize that by having people go to college you are in fact helping out the workforce. College delays thousands of high school grads from entering the workforce by 4-5 years. If you think it's difficult to find a job now, imagine an America where a large portion of high school grads enters the workforce rather than going to college.
In the grand scheme of things life is short and personally I would not recommend college to anyone that doesn't have some sort of plan unless they come from privilege and want to hang out at the Middlebury's and Amherst of the world if nothing more then to network and rub elbows with other country club kids.
I know nothing about rubbing elbows with the rich and privileged since that was not my scene but there is nothing wrong with networking.