1. Mortgage contracts are too complex for a layperson to understand. Often the amount of time people are given to sign them is less than it would take to read the entire contract through just once. 2. Getting a mortgage is an instance where the seller is also the advisor (similar to an auto mechanic or a doctor). 3. Consumers were actively advised to take out mortgages that the seller knew were more expensive than the consumer could afford. 4. If a predatory auto mechanic deliberately advised a customer they needed repairs that they did not, that would be fraud on the part of the mechanic. The same thing applies to predatory lenders.

(There certainly were people who just made bad decisions. But there was also widespread, documented fraud on the part of lenders.)