If Firefox offered a .deb for $OS on their homepage, and Grandma attempts to install it while running $OTHEROS, then likely she will either 1) fail or 2) break her system. That's a worse user experience than a .tar.gz.
Asking Firefox to maintain packages for every outdated Debian-based distro is unreasonable. Nice to have, yes, but unreasonable to ask.
If Firefox offered a .deb for $OS on their homepage, and Grandma attempts to install it while running $OTHEROS, then likely she will either 1) fail or 2) break her system. That's a worse user experience than a .tar.gz.
Asking Firefox to maintain packages for every outdated Debian-based distro is unreasonable. Nice to have, yes, but unreasonable to ask.