Github is not a software distribution platform, it was never meant to be one. It's a developer platform for code distribution and collaboration. And UI is designed around that.
A lot of projects use it as a distribution platform, but they're wrong - it's always better to have a web page with simple download button for casual "ordinary" people.
But, this case is special: this mostly harmless tool is designed and almost exclusively used to stalk / doxx / hack people =|. So, it's not in developers interest to make it widely available and easy to install.
Sorry, I meant to write that Github is not a software distribution, but a code distribution platform.
And 'mostly harmless' as in it's not inherently malicious - you can use it for harmless stuff. It's merely a tool.