The culture teaches us from our earliest days "Don't put all of your eggs in one basket."

An economic decision should be made on the basis of its economic basis not the social cachet of the financier.  To the extent that the investors viewed themselves as part of an "in" group belonging to the right clubs, organizations, charities, they were behaving at best as a high school clique and, at worst, as a privileged elite.

Madoff's returns defied all logic.  The phrase "if it's too good to be true, it probably isn't" applies.

As well, some of the investors may have believed that Madoff was cheating by using a form of illegal insider trading know as front running.  

These people should not be pitied, helped out, rescued, or kept from the consequences of their folly.

At best, the were stupid, snobs and suckers.  Some may well have been sociopaths.