Why aren't clients fleeing Goldman Sachs?

I think there are two main reasons.

The first is that Goldman has two types of clients: banking and trading. Banking clients are generally unaffected by Goldman's trading misdeeds. These are very different businesses. Investment banking does not happen on a trading floor, very different services, very different people etc. Everything is different.

The second is that professional trading clients understand that Goldman is not there to look out for them in deals. Goldman acts as a counterparty, not as a fiduciary advisor who is obligated to fight for the clients' best interest.

I think there is a common misconception that Goldman acts sort of like a manufacturer of widgets, that these widgets turned out to be broken, and that Goldman should now be held responsible sort of like a Chinese manufacturer of poison-laced toys. The Goldman-counterparty relationship is very different.