Because a lot of people use github issues and milestones as a way to gauge what is needed to be done for what release, and the ability to order by priority is a

Because a lot of people use github issues and milestones as a way to gauge what is needed to be done for what release, and the ability to order by priority is a great option. You may think it's trivial and doesn't deserve the front page, but many people do. Clearly.