The 10am-10pm work culture is a market inefficiency. It biases recruiting towards people in their twenties, leaving experienced and capable family people on the table.

It's a filter. These companies want people who don't have the leverage or skill to push back-- eager beavers who can take on the worst work without complaint. Despite complaints about managing "Millennials", they're actually the easiest to manage because (a) they don't have any leverage, and (b) the job market for college grads was terrible from 2007 to 2010, and the graduation-date effect is formative and lasts for a long time.

Investment banking ("eye-wanking") is the worst in terms of taking advantage of "eager beaver" young people who don't know their rights. The appeal of a student to an I-bank is that a student is coming out of an environment where deadlines are well-tested and the same for everyone in the class, so missing one is a reflection on the student. It makes a "deadlines are deadlines" culture where people will work 120-hour weeks for a month to meet arbitrary milestones palatable. Someone with more work experience would look at the 120-hour schedule and say, "What idiot came up with these deadlines? Hire more people or set a realistic schedule!" That's what I-banks don't want, because one "mole" who knows his rights can "corrupt" everyone.

Here's the eager beaver/eye-wanking timeline:

22-23: work 80-100 hours per week under the assumption that the miserable grunt work being given to you is actually a valuable "learning experience" and not just shit no one else wants to do.

24: burn out. Live with parents if middle-class or higher in origin; drive a cab if working-class or lower.

25-26: re-enter the eager beaver game. Lie about your "gap year" at 24 by filling it with a nonexistent non-profit shell-company charity your parents (if wealthy) or friends (if not) created. You've down-shifted from the extreme culture of entry-level investment banking to the more "professional" environment (i.e. unlike among the IBD analysts, it's no longer acceptable to use "f----t" as an all-purpose insult; "piker" is used instead) like private equity or management consulting, but the hours are just as bad and now there's travel to uninhabitable wastelands like Dallas in August. The upshot is that you've discovered that you can spread 25 hours of work across 100 hours of in-office time and no one knows the difference. Still, you long to see the sun. Same shit, different stink.

27-28: the expensive and intellectually deadening variety of burnout known as "business school".

29-33: still working in soulless white-collar job, now for middling six-figure salary. The work is still awful, and the hours are bad, but you can leave around 8:00 if you check your Blackberry at home. Also, you can delegate the truly punishing work to junior people, and that schadenfreude becomes for you what a calm breakfast is for a lot of people-- a simple joy that keeps you going.

34: start to feel impending signs of burnout, which takes longer to set in, but is more severe if it occurs, as one ages. Assault a stripper because it's more respectable among your peers to go to jail than to down-shift one's career voluntarily.

35-36: Jail, which (thanks to your expensive lawyer and minimum security prison) is really a networking opportunity in disguise. Build the connections that will make you a "made man" when you get out.

37-42: Hired at "Managing Director" level. You've made it! Annual compensation gets into the low 7-figures, which means you can easily afford the ridiculous guilt presents on display at FAO Schwarz for what's-her-name-again that are guaranteed to be age-inappropriate in one direction or the other by at least 3 years. Realize, to your chagrin, that there are levels above MD ("Executive Director", "Principal Managing Director") and that the "up-or-out" rule still applies: if you're not ED by 40, sayonara!

43: "Retire". Massive heart attack on 16th day of retirement. Die alone. Doctors think you're almost 70 when your body comes in.

44+: Realize hell is similar to the pointless office job you had at 23. Walk around hell saying, "This is nothing; when I was at Goldman we...". Become so insufferably annoying that your behavior is judged to be unacceptable even for hell. Your red stapler is thrown into the Ninth Circle and Judas, Cassius, and Brutus use it as a prop for a mean-spirited game of "Monkey in the Middle".