1. only packaging once, opposed to making a .deb, a .rpm and so on.
2. as soon as its in the language repo, it's available everywhere. Even if I make an apt-get package, I'd have to wait for Ubuntu/Debian/others to include it in their repos. Or I'd have to host a ppa, requiring users to search for it and add it to their package manager. RPM fusion and AUR simplify that, but it still seems hard to have your own packages on .deb systems.
Also because people are complacent with something that works well most of the time, but not all of the time. (where most applies only if you're running the latest stable Ubuntu)
1. only packaging once, opposed to making a .deb, a .rpm and so on.
2. as soon as its in the language repo, it's available everywhere. Even if I make an apt-get package, I'd have to wait for Ubuntu/Debian/others to include it in their repos. Or I'd have to host a ppa, requiring users to search for it and add it to their package manager. RPM fusion and AUR simplify that, but it still seems hard to have your own packages on .deb systems.