At lots of institutions risk management is a joke (see JPM's CIO blow-up). But at the GOOD ones, risk management has a seat at every table. It's up to YOU to make sure those a**hole traders aren't going to explode the bank and lose their client's money. Not to mention the shareholders.
Seems pretty ethical to me.
If you still feel bad, decide what an "appropriate" amount of money is for yourself, and give the rest to charity every month.