They didn't revert, they moved on to the next version. The next version just sucks.
You can't keep running software that isn't supported for very long because there are no patches and no tech support and also whatever it talks to will quickly make changes that break the connections to the software. The only thing that keeps a particular version of software functional is the O&M tail.
In some cases like Windows your key will fail -- they won't let you keep running old software. That's okay if you're Joe Schmoe, you just find a workaround. But if your product or service is commercial that violates the EULA and you're in trouble or in any case without recourse if anything happens that damages your users.
It's the same reason you can't be below code if you run a hotel. I mean, yeah... you can be... for a while. But it's an excellent way to get into serious trouble.