Freelancers often have lawyers who: write their contracts, adjust them for new clients, fight over breaches, etc. Founders will have lawyers who do something similar for them via-a-vie their companies. When you have a steady stream of work, you can often ask them to do little things like this as a favor, just like they might ask you to help them with some tech thing.

I think those groups just happen to be massively over-represented on HN.