Firefox 53.0 finally drops support for XP and Vista
After Microsoft has already (thankfully) dropped support, also other developers are following. The next one is Firefox, which is pretty popular in Germany, if not the most non MS browser used in our country. However Mozilla chooses to support Firefox users with the ESR (Extended Service Release) version of Firefox, but I doubt many average users will be aware about that change nor have the knowledge that they have manually to switch the browsers by uninstalling the old and and replacing it with the ESR release.
Windows XP and Vista are no longer supported. XP and Vista users running Firefox 52 will continue to receive security updates on Firefox ESR 52.
“The good thing about computers is that they do what you tell them to do. The bad news is that they do what you tell them to do.”
– Ted Nelson
That should happen one day. And seemed that's day happened.
Xp and Vista are very old, that's why there not many users are using them. It's absolutely normal to drop old things, cause you need to work with new one.