The linked blog post is really about bad customers, and either firing them, or not accepting them in the first place. As a freelance developer it seems easy enough to say if someone's going to pay you your going rate to build something, accept their money and build what they're asking.
The problem is that in reality, clients like that often turn out to be bad customers. They don't know what they want, make all the excuses to avoid paying on time (or worse, offer "equity"/revenue share), and you end up spending all your time and energy supporting them - just one more little change and I'll pay you - and not by working on actual client projects.
Sussing out which clients are like that is up to you as a freelance developer, and it's a skill that isn't programming but is well worth your time to develop.
The problem is that in reality, clients like that often turn out to be bad customers. They don't know what they want, make all the excuses to avoid paying on time (or worse, offer "equity"/revenue share), and you end up spending all your time and energy supporting them - just one more little change and I'll pay you - and not by working on actual client projects.
Sussing out which clients are like that is up to you as a freelance developer, and it's a skill that isn't programming but is well worth your time to develop.
(Putting the funds into escrow only goes so far.)