If you work in finance, then not living in Manhattan means you're not "serious" and will be passed over for promotions, etc.
Basically, high rollers are expected to live a high-roller lifestyle. If you display signs of frugality it means you're still thinking like a poor person.
Not that I disagree, but there's also the practical angle: if you spend 2 hours commuting every day, that's cutting into the hours you can show that you devote to work.
That's not true at all. I know plenty of people working in upper echelons of finance companies that live in outer boroughs, New Jersey, Long Island, Westchester, etc. I would actually say most are.
Basically, high rollers are expected to live a high-roller lifestyle. If you display signs of frugality it means you're still thinking like a poor person.