There's some interesting game theory at work here. I remember learning in the early days of ransomware that the hackers would typically provide excellent customer service to the targets. They'd always promptly respond to emails or phone calls, and they'd even walk you through the process of buying Bitcoin to send. The premise was that you'll get the highest revenues if you make it as easy as possible for people to pay you - and establish a reputation for actually unlocking the data once you're paid!

Of course, just taking the money and running is a much higher-margin business, but it relies on that established reputation-building. Maybe a good analogy is counterfeit sellers on Amazon.