The thing is, it's an appropriate ending if, say, you only watch the first film in the trilogy and then skip right to that ending. After all, the series started out as much more of a horror franchise, but stopped taking itself seriously right around the time Ash's hand got possessed and he was forced to replace it with a chainsaw. From then on, it became the goofy festival of blood, slapstick and one-liners that made Bruce Campbell a cult hero.
Oh, it still makes perfect sense to have him fuck up the potion, or to even make it so that he wakes up in a future full of zombies that need a good chainsawing. Instead it ends like some kind of Shakespearean tragedy, which is, uh, not exactly what we came to expect from the series.
There's not even a chainsaw-hand in sight.