It's not necessarily about "good UI design", but much more about taking all measures to prevent accidental deletion and ensure that the user is fully aware of what he isthey are deleting.
This blog entry here captures it quite well:
Instead of giving users a confirmation button that they could mistakenly press, give them a text field and ask them to type the word “delete” to confirm. When the user types “delete” in the text field, there is no doubt that they want to delete. There is no accidental pressing of the delete button. There is no regret when the user deletes, because the confirmation text field makes them certain about what they’re going to do before they do it.
How to Make Sure Users Don’t Accidentally Delete - UX Movement
Sure, pressing a button is easier, but that always leaves the chance that you misread the name and delete the wrong item.
When you have to type out the name (or even copy paste it), you can be 99% sure that a user won't do that mistakenly. They would realize it at the latest when highlighting the name for copy-paste.
Besides that, this is usually only used for very critical deletion operations. These happen very rarely, so the argument about making it easier or less annoying doesn't really hold there.
Here are some related questions: