Coolweb came the closest.
Generally speaking, intelligent people think that most other people are stupid (and they really are, by comparison).
Dumb people think that 'people are smart' (and they really are, by comparison).
So according to my theory, the top suits at Ditech realized that their mortgage terms were so uncompetitive, only a dumbass would sign one of their contracts. They also found that dealing with intelligent potential clients is mostly a waste of Ditech's time, as the smart potential client usually realizes it's a bad deal, and goes away to shop elsewhere.
Therefore, the slogan 'people are smart' is a way to filter out smarter potential clients (who find the slogan absurd), while bringing in dumber potential clients (who readily agree with the slogan). Does that make sense?