I'm far more interested in societal growth than individual character building.
I don't see how it's even remotely relevant for someone to have the skillset or durability that comes from working 60 hour weeks on minimum wage for 5-10 years when that's time they could be spent doing something that matters to the rest of the world. Getting an education and doing something more important than standing at a gas station register, or maybe having one decently-paying job and then spending some extra time volunteering, if you've got the extra energy to spend, etc.
I'm basically saying it's kinda ridiculous to me to enforce character building in this way. I agree with Meikle. There's no reason that in a prosperous society and prosperous circumstances that anybody needs to spend their time building up from the bottom. Our society continuously tries to become more prosperous for that reason. Why should anybody waste ten years trying to get by when they could have been the next genetic scientist?
I realize this post takes more radical views: I'm not even trying to claim that all the views stated here are right, but I'm just trying to offer another one. Hard work does not have to mean struggling to survive. Struggling to survive is not the only way to build independence and good qualities, and "Nothing is as motivating as having to take care of yourself" is just a felonious statement. Really? Really, nothing else in the world works?
Here's my example: I want to be a published writer. I would much rather take, say, maybe two years of mooching off my family and having the freedom to write, publish, and establish some income (this is just an example and surely an optimistic one at that), and be able to turn around and repay my family for the support they gave me and support them in their times of need. That will be worth a fuck ton more to me than struggling for the next five or ten years out of minimum wage jobs trying to pay rent and feed myself, constantly wanting to pull my hair out, and never having the time or energy to write, and never having the luxury to help those around me.
I'm just not buying the pricelessness of that kind of life experience. Is it great? Yes. That doesn't mean it's the best, or even close. That doesn't mean there aren't better options.
I've learned a lot of life lessons from being emotionally abused. There are things I can look at and say, "I learned from that." But I can't say "That made me a better person" anymore. Because it made me better than what? Better than who I would have become if I had felt loved and secure? Better than if I hadn't been neglected?
I feel it's the same scenario. There is plenty of life experience and lessons to be taken from poverty and hard work via necessity, but desperation does not a hero make. Congratulations if you hit rock bottom and came back up without killing yourself or becoming a junkie! But that doesn't make you any better than someone who didn't have to deal with that kind of event—and it certainly doesn't make you better than the people who hit rock bottom and didn't make it out all right.
In summation, I don't think, say, that it's "bad for people to learn sacrifice, the value of hard work and learning how to work towards their goals" in the ways that have been discussed, but I disagree that being forced to do so alone is necessary or even optimal.