You know, I do think that there's a benefit to shedding light on your personal situation if that can help inform others - ie, if this friend went into heavy debt for a not-so-lucrative degree, it's reasonable for him to share his experience so others are better informed and don't follow in the same path. So, if (none of the following is true about me) I went into 100K debt on a psychology degree, and now I rue the situation because I have a low-paying job and wish I could go back in time and make different choices (pick a different major/school, not take out tons of loans), it's good if I'm clear with friends and family about what this debt load means for my life, and why I wouldn't advise someone else to take the same path.
I have a lot of compassion for people who didn't have the education, thoughtful and dedicated parents, and physical and mental abilities that I did/do. The way I see it, there are two (mostly) orthogonal components to our success: (1) personal circumstances, ability, and effort & (2) systemic & macro factors. Some people focus heavily on one or the other, but it doesn't feel right not to acknowledge both components. So I think think that's it's possible to simultaneously critique what this 'friend' is doing about housing & expenses, and to acknowledge the larger problem of the system where teens are legally able to take on tons of debt without understanding the impact on the rest of their lives, and where federal loans are propping up the rising cost of college.
I will say that I see myself & my peers having a hard time delaying gratification and being able to view the bigger picture. It's pretty true that among my mostly middle/upper middle class friends, it's standard to go out lots for dinner and drinks, to have nice phones, etc. I and many of my friends are immigrants, so I remember reeeeally well that my parents (& I) had a really different lifestyle when we first moved to the US, that the very comfortable life my parents now have is not a life they could've afforded at my age. But I think it's easy to forget that, and to feel as though your life standard should be at where your parents/you growing up, are at.
So I guess I don't have a lot of sympathy for someone who doesn't see that sacrifices are necessary & that your lifestyle should be determined by what you can afford firstly, and what you want secondarily. For example: don't start your housing search saying you want a one bedroom with X. See what you can reasonably afford, then see what your options are, whether you need to find roommates, etc. Complaining for the sake of complaining isn't doing much to advance your life in the direction you want - better to harness your experiences and learnings to change your behavior in the future, rather than get stuck lamenting the past.