It's always sad to see a project failing. There are other alternatives, both to a KDE linux distro (i.e: openSUSE) and gnome/ubuntu (mint being my favorite).
It's a business decision I understand, they want to shift focus completely to ubuntu, especially since they are losing a huge user-base over their last gnome3 releases.
It doesn't mean the project is failing. Kubuntu had only a single developer from Canonical, and numerous other developers. This just means that Canonical doesn't feel like funding a KDE desktop anymore with that one developer. It doesn't mean the project is ending or anything.
You're right, but it means the project will (probably) become less stable. One less full time individual probably means less testing and might require you to use older packages or build them yourself.
It's a business decision I understand, they want to shift focus completely to ubuntu, especially since they are losing a huge user-base over their last gnome3 releases.