The following is entirely my opinion, and not based on empirical evidence, with that said...
I think the issue is that a lot of people don't believe they have a choice. When you are getting hired, make a point that you are not willing to work more than 40 hours a week (unless as completely necessary such as an actual emergency which requires your intervention), but for the hours you do work, you will put in your best effort. You're signing a mutual contract, not indentured servitude, serfdom, being "sold", etc.
It would be plain foolish not to hire someone like that (if they did in fact put in their best work). For some reason everyone thinks they have to be a slave to their company, but any company that recognizes their employees wishes will be able to reduce turnover (which can be very expensive) and in-turn have a higher morale which can improve performance.
I also think that parents are not teaching their kids good skills. I don't recall my parents saying anything other than "work hard" and "do your homework". They didn't tell me how to navigate the real world after school, I figured it out on my own. I learned how to find a company that not only wants me to work for them, but that I'd like to work for them as well. What questions to ask in the interviews, what signs to look out for that raise red flags on how employees are treated, how to research companies to see what the employees say about it and what benefits they may provide.
As a result I probably don't make as much as I could be, or I'm not as far in my career as I could be. But that's okay, because I get to go home at night and not worry about work, and spend time with my family. I also have the option to move jobs at will at any time, for any reason. I was in a job once that wasn't the perfect fit, and found an even better job as a result of the experience I gained working there for a fairly short time.
I love my job now, and I don't know what I would do without it. I'm very lucky that someone has put in the thousands (or hundred thousands, millions, tens of millions?) of dollars to create a business that is able to take advantage of the skill I have without me owning my own business.
Lastly, people are easy to be bitter and resentful. I'd hate to look back and feel like I was taken advantage of for the majority of my life, or missed out on important life events for a job that didn't matter.