To me it's because of the different roles of the job

writing text on a mockup is usually the UX writer job, designing the interface is the UI designers job, if you go out of your way to write something like this, you know they're doing it on purpose, or at least they know what they're doing enough to push the user to act..

Asshole design to me has to do with the functionality like for example, you click on a button and it does something else, or designing a fake button where the user clicks but it doesn't do anything.. It's blank.. Or a piece of artwork that's offensive.. Etc

This is asshole writing ( it's more direct ), so that's why I said designers being assholes