It makes sense from a pure UX perspective. But of course the real goal of GitHub is to make money, and their paying customers are mostly corporate entities using it for enterprise development. Unless those companies decide that a download button/better release feature is desirable, it's not likely to happen.

Most corporations tie GitHub into their own build system so such a feature isn't likely to be considered useful. They pay for GitHub to reduce development costs, which is why GitHub spends so much effort on analytics and the dev experience instead of open source/public users.