>I often think scary popup boxes are enough to get people to think about what they're doing
This would entirely depend upon how often it shows up. The more often it shows up when the scare isn't relevant, the less people will pay attention to it.
>the distractions ("Type this repo's name", etc) just go away
I think it shows that what one types needs to be relevant information. In this case, due to the similarity between when the author would've been asked if they did what they were intending to do and what they typed to do what they actually did, we can judge the prompt isn't enough. If this also asked you to type in the number of git stars you were about to lose, that would've been enough to make author recheck exactly what they were doing.
This would entirely depend upon how often it shows up. The more often it shows up when the scare isn't relevant, the less people will pay attention to it.
>the distractions ("Type this repo's name", etc) just go away
I think it shows that what one types needs to be relevant information. In this case, due to the similarity between when the author would've been asked if they did what they were intending to do and what they typed to do what they actually did, we can judge the prompt isn't enough. If this also asked you to type in the number of git stars you were about to lose, that would've been enough to make author recheck exactly what they were doing.