I get the feeling that people who snub factory jobs live too high on the economic ladder to realize how much of a step up that sort of job can be for a person.
More importantly, Foxconn's agreement with WI states that up to 93% of workers can be paid $15/hour. That's barely enough to live on even in Wisconsin.
If Foxconn were legally required to pay 50k+ with benefits for factory work, I would happily agree with you. But that's not what the contracts say. The contracts say basically everyone except management and engineering can be paid $15/hr.
Also, the Amazon fulfillment center just a few miles from the site of Foxconn's new plant pays $15/hour and is constantly hiring. So we're basically paying 4.1 billion for... a bunch of jobs that are roughly equivalent to openings that already go unfilled just down the street.
Finally, remember that we're talking about 4.1 billion dollars. That's a lot of healthcare/education/infra/small business development/etc. opportunity cost.
I also agree with you that the working conditions for factory workers have been degrading significantly for the past 20 years or so.
$15/hr might be barely enough to live on, but it's still better than minimum wage. Also the nature of working on an assembly line is different from working in a fulfillment center. Being able to tell people "I help build those" has more pride behind it than telling people you run around shoving stuff into boxes for people.
I'm in Iowa, which I imagine is similar cost of living to Wisconsin. My dad worked in factories almost his entire working life. I stand by my statement that if you are lucky enough to land a full time factory job, it can be a viable way to raise a family.