My answer's pretty simple: No, the game development is not dead - but if you have to ask that question, then you should consider acting as if it was. The purchase page is pretty clear: you pay for where the game is now.
As others have said, even with the flaws in the current version, I find it to be a more polished and complete game than some officially-released-and-done games I've played. Will the next patch be better? Yes. Should you be holding your breath waiting for it? No.
Look, this bit may get a bit morbid, but it boils down to: there's one primary developer. This isn't even a small studio working on a game, here; there's a single point of failure and an -expletive- pandemic going on. There is exactly zero guarantee that the next patch will ever even happen. It's good odds that it will, and Alex is actively working on it, but if you feel you need that next patch to justify your purchase... then don't purchase yet. (Or if you already have, then judge the game based on how much fun/playtime you've already gotten out of it.)