The way I understand it is that it builds on the idea of using bitcoin paywalls as a DDOS deterrent.

For example, if you require 1000 sats for trying to open an SSH connection to your machine you effectively limit capabilities of unwanted people connecting to you.

And if you think what kind of 'resource' makes sense for such use-case, bitcoin is the one. It's neutral (for example if you would use USD for paywalling, US could attack you as many times as they want, because they can mint new units). It's physics-bound, so there is upper bound of how many trials they can use (USD has no upper bound).

Think about 'waiting in a line to a doctor'. Can the doctor be DDOSed? Not really, his waiting room won't accommodate 1000000 people - there is not enough 'physical space' resource to fit that many people.

Because bitcoin is physics bound as well you can replicate this kind of limitations in the cyberspace in some sorts.