Steep recessions and sluggish subsequent growth have a really negative impact on the wealth and incomes of a wide range of people. That includes wealthy finance guys and jobless young people and underwater middle class homeowners and everyone. And the natural human instinct when you wind up with less pie than you thought you could reasonably expect is to assume that the people in charge gave your pie to someone else. So Wall Street feels that run-amok populism has impoverished them (relative to expectations) for roughly the same reasons that Obama's liberal critics feel that his constant succor of the banksters has impoverished them—everyone is poorer than they thought they were going to be.
Previous Dish on why Wall Street donors have ditched the Obama campaign here. Meanwhile, Peter J. Boyer and Peter Schweizer investigate the administration's failure to hold Wall Street accountable (for instance, "financial-fraud prosecutions by the Department of Justice are at 20-year lows").