This is factoring, not payday loans. As the author investigates, he finds this out as well.

I've done plenty of freelance work and I deeply know the pain of getting paid late, but as others have pointed out, dealing with a larger business results in net 30/60/90 terms, when things are going well. The fee you pay to the intermediary is justified.

Now if the only option to ever get paid was to pay an intermediary a cut of your salary, well then that would be a major issue. But otherwise this is the freelancer paying an intermediary for a) quicker access to funds and b) reducing the (albeit often small) risk of the client not paying.