No that's exactly how open source works. They are under zero obligation to wake up tomorrow and continue to work on it. Everyone is lucky they open sourced it, and anyone else is welcome to pick it up where they left off. Contributing a impressive piece of work the community is an accomplishment.

Disparaging them and suggesting people should not trust them in the future for not providing ongoing maintenance, when that was never part of the OSS deal, shows a misunderstanding of what OSS is. Pay them for a maintenance contract, or don't expect maintenance. Stop complaining they didn't fulfill some social contract that existed only in your head.