You raise a good point, addictive technology is not necessarily for profit. The difference is that being addicted to a decentralized technology means that no one actor can control you. Usenet was a distributed system with a distributed network of control.

The analog I would say is being addicted to Chess, which is decentralized activity.

The fact that it was a distributed system, impossible for any single entity to control, didn't AFAICT ameliorate or moderate the intensity or the duration of my compulsive over-consumption of Usenet.