He's not writing "extract as much money from other people as you possibly can". He's making a subtler point, similar to Hofstadter's Law, in that you're not cha

He's not writing "extract as much money from other people as you possibly can". He's making a subtler point, similar to Hofstadter's Law, in that you're not charging enough, even if you know that you aren't! So, the point isn't too extract as much money from other people as possible. It's too charge more than you'd otherwise be comfortable charging because, even when you do, you may still be under-charging relative to the actual costs required and value provided.