Well, when you've got a large list of things stored on a computer, and you want them displayed in a certain order, automatic sorting (after you assign a priority) is a lot more useful than having to rearrange them manually.
I thought assigning priority labels is manual anyway?
I mean, if you want to build a natural language parser that counts how many times the words "URGENT" and "HELP" appears in the issue and then automatically reorders it, you can do that with the Github issues API anyways, right? I don't know of existing bug trackers that make priority automatic.
You can filter based on labels in github issues, if that's what you meant.
Well, when you've got a large list of things stored on a computer, and you want them displayed in a certain order, automatic sorting (after you assign a priority) is a lot more useful than having to rearrange them manually.