A myth.
Here's a book from an ex FBI hostage negotiator. It narrates some real case stories from the inside, it's well written and quite interesting. https://www.amazon.co.uk/Stalling-Time-Life-Hostage-Negotiat...
So “outcomes are worse if you don’t” is not relevant. Several times as many terrorism incidents with better outcomes on average is not what most people would consider effective anti-terrorism.
E.G. http://www.bbc.com/news/uk-england-leicestershire-42667451
Details of "hundreds, potentially thousands" of vulnerable people, including children, have been emailed to taxi firms by a council.
Just for one example from the headlines.
The digital version of kidnapping would be the hackers who stole Netflix shows and tried to random the money from them.