Like someone pointed out up thread, I don't think it makes sense to see that salary as X per hour, or even take into account the number of hours they work.
It's an investment they're making in their (very immediate) future and unfortunately Investment Banking can have a culture of presenteeism, especially if you're a lowly first year analyst.
So you don't clock watch and get paid handsomely for working under pressure and having very little free time. Whether they're overpaid or not, is a whole different kettle of fish.
I know roughly how much each IB pays in bonuses at different levels and I have no concerns about their employees' hours of work.
I can't remember the last time I had a "start time" or a "finish time" at work; if I or any of my colleagues feel like going to the gym at lunchtime for 3 hours or need to go to the doctor in the middle of the day, we just go and no one would dream of saying anything.
But the flip side is my job has always been results' orientated so they don't have to control our time; we have to deliver results (and revenue) or we're sacked. So we could be working 80 hour weeks or entertaining clients until 5am and have a meeting booked for 7am.
Having said that, I'm sure that plenty of people can sleep easy at night knowing that they'll have a job next quarter and often we don't have that security. Swings and roundabouts.