I'm curious what the answer was. I've read plenty about how the boutique finance sector is basically a parasite that only benefits a small cohort of already wealthy individuals, would like to hear what the other side has to say.
An example is onions futures; see https://en.m.wikipedia.org/wiki/Onion_Futures_Act and check the onions price history: https://fred.stlouisfed.org/series/WPU01130216/ compared to a commodity where futures trading in common, like corn: https://fred.stlouisfed.org/series/PMAIZMTUSDM where there are price swings but the volatility and frequency of the swings is lower.
I’m a layperson, not involved in finance, but this is the value add I most commonly hear about.
For instance, the oil/car industry pays for basically none of the large negative externalities they create. In this case, I hazard that futures industry captures more value than they create. And that value is extracted from other players in the vertical chain, particularly farmers.
When I was an undergrad, I interviewed at a then-very small, now-very-prestigious quant firm. In the last interview or so, I asked the quant head something like, “but what value do you provide to society?”
He said, “we provide liquidity.”
I turned down the job they later offered and went to work at a software company that sells a thing people buy.
I would prefer the price of onions - seems like the price is a lot more stable other than a few points out of the year where it is very high. For those times, I could choose to have a small store of onions or go without.
For the price of corn, if the price is high, chances are it will be high for a while, so I'll have to go without for a while...
What do other people think?
Sounds like you gave an answer that didn't mention that at all, and may have presented the firm as merely taking advantage of other people's mistakes to make profit. Clearly that's not how he saw it, and the VP correctly guessed from your social media that you may not actually have understood the part of the finance industry that you were applying to work for. The question was to check whether you'd actually be enthusiastic about the work you were doing and you did indeed fail it.
This would be like if you turned up at Google and an interviewer said, "What do we do here" and you said "exploit data to profit from people's ignorance" and when they gave you a second chance you couldn't answer.
Frankly you can't get a job at most firms if you can't explain why you think the company should exist.
I really enjoyed "The Rational Optimist" where it explains things like trade, which tends to make everyone wealthy, while generally the people trading think they are both getting the better end of the deal.