Enforcing contracts is expensive, and if someone obtains a significant amount of goods and services the money may not be recoverable even if there's a contractual ability to do so (as it doesn't exist), people may simply go on the run, people may engage in outright fraud.

Trust is vital in a business relationship. Contracts are a useful backup against a legitimate body, but they are not much use against someone who has literally a proven track record of going on the run from law enforcement.