All is vanity
There is a tendency all industries to think we are better than anyone else, because we don't really know what other industries do. If they spent a while looking into the coding challenges behind running a power station, simulating a logic circuit with 2 billion transistors, debugging an air traffic control system, controlling CERN etc., Wall Street techs might have to re-calibrate their self image.
If it is like the City of London, then the inflated salaries offered by Wall street exist because of the market: the job does not require the best brains, it requires people who are willing to put up with the large drawbacks on offer: huge, unpleasant commute on dirty, overcrowded public transport, long working hours, poor treatment, unpleasant working experience, and a pisspoor quality of life. No wonder they drink.
"what they left behind was so convoluted, overly complex, and incomprehensible to anyone but themselves that the remaining team members, all highly skilled, had no choice but to scrap it completely and start from scratch — months of labour and tens of thousands of dollars (at least) up in smoke"
Wall Street doesn't know about basic software engineering ?